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Class / Case #
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Vol.
Serial #
0062 83694
1
164
ONLY
8/11/1274166
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DEPARTMENT OF THE AIR FORCE
HEADQUARTERS UN1TED STATES AIR FORCE
DIRECTORATE OF INTELLIGENCE
WASHINGTON 25, D. C.
15 February 1949
AIR INTELLIGENCE REQUIREMENTS
MEMORANDUM NUMBER 4
UNCONVENTIONAL AIRCRAFT
PART I - GENERAL
1. PURPOSE
The purpose of this memorandum is twofold:
a.
To enunciate continuing Air Force requirements for information pertaining to sightings of
unconventional aircraft and unidentified flying objects, including the so-called "Flying Discs."
b.
To establish procedures for reporting such information.
2.
RESCISSION
Department of the Army Collection Memorandum Number 7, dated 21 January 1948, and letter,
CSGID 425.1, dated 25 March 1948, both subject as above, which have been transferred to Air
Force agencies for action, are herewith superseded.
3.
REPORTING
a.
General
(1) As complete an answer to the requirements enunciated in Part II, as may be procur­
able, should be dispatched by means of electrical transmission immediately afte:' sighttngs.
(2) Supplementary reports should be forwarded as availabl e by the most expeditious means
consistent with the importance of the information reported.
b. Major Air Commands (Overseas) and Air Attaches
(1)
Initial and supplementary cabled reports will be transmitted to the Dir ector of Intelli­
gence, Headquarters United States Air Force.
Cables will contain the phase, " Pass to
COMGENAMC WRIGHT-PATTERSON AFB, DAYTON, OHIO, ATTN: MCIAXO- 3."
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C9-~892, AF

..
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(2) Supplementary written reports, prepared on AF Form 112, will be forwarded to the
Director of Intelligence, Headquarters United States Air Force.
(3)
Commanding General, Air Materiel Command is authorized direct contact with major
Air Commands (overseas) and organizations under their control in connection with the
development of information on this subject.
c. Major Air Commands (ZI)
(1) Reports will be forwarded direct to the Commanding General, Air Materiel Command,
Wright-Patterson Air Force Base, Dayton, Ohio, Attn: MCIAXO-3 by installations receiv­
ing information pertaining to the requirements enunciated in Part II.
(2) Copies of such reports may be supplied the Command Headquarters of the installation
concerned.
(3) A copy of all reports sent to Air Materiel Command in accordance with these instruc­
tions will be forwarded at the same time to the Director of Intelligence, Headquarters
United States Air Force.
(4) Written reports will be submitted on AF Form 112.
(5) Commanding General, Air Materiel Command is authorized direct contact with major
Air Commands (ZI) and organizations under their control in connection with the d~velop­
ment of information on this subject.
d. Non-Air Force Agencies
(1) Addressees otqer than those of the United States Air Force are requested to forward
reports direct to the Commanding General, Air Materiel Command, Wright-Patterson Air
Force Base, Dayton, Ohio, Attn: MCIAXO-3.
(2) In order to reduce the time factor involved in transmission of this type of information
it is requested that, wherever communications facilities permit, subordinate elements be
authorized to communicate reports direct to the Commanding General, Air Materiel Com­
mand.
PART II - REQUIREMENTS
General
1. Date of sighting.
2. Time of sighting (zonal by 24 hr. clock).
3. Where sighted (observer's position):
a. Ground
(1) City, town.
(2) Distance and direction from city or town, road, intersection, etc.
(3) From building (story), yard, etc.
(4) Map coordinates (if feasible) showing latitude and longitude.
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b. Air
(1) Type aircraft, speed, altitude, direction of flight.
(2) Distance and direction from city, town or known landmark.
(3)
Clock position of object from observer's aircraft.
(4) Latitude and longitude.'
c. Sea
(1) Latitude and longitude.
(2) Proximity to land.
(Name city, country, etc.)
4. Number of objects.
Formation type (if any), sketch if possible.
5. Observable celestial phenomena or planets that may account for the sighting. (Local facilities
or organizations which follow such celestial phenomena should be consulted for such information.)
6. Distance of object from observer.
a. Laterally or horizontally.
b. Angle of elevation from horizon.
C.
Altitude.
7. Time in sight.
8. Appearance of object.
a. Color.
b. Shape.
(Sketch if possible)
c.
Apparent construction.
(Of what material or substance)
d. Size.
(1) Estimated size.
(2) Size as it appeared from observer's view.
(Compared to known object)
9. Direction of flight.
10. Tactics or maneuvers.
Vertical ascent or descent, horizontal, oscillating, fluttering, evasive, aggressive, erratic, etc.
11. Evidence of exhaust.
a. Color of smoke.
, b.
Length and width.
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c. Odor (if any).
d. Rate of evaporation.
e. Does trail vary with sound? (spurts)
12. Effect on clouds.
a. Opened path thru clouds.
b. Forced cloud or mists.
c. Reflected on cloud.
d. Showed thru cloud.
13. Lights.
a. Reflected or attached.
b. Luminous
c . Blinked on and off in relation to speed.
14. Support
a. Wings.
b. Aerodynamic list of fuselage.
c. Vertical jet.
d. Rotating cylinder or cone.
e. Aerostatic lift (balloon or dirigible).
15. Propulsion.
a. Propeller or jet.
b. Rotor.
c. Aerodynamic vanes (flapping or oscillating) (Katz Mayer effect).
d. Visible exhaust or jet openings.
16. Control and stability.
a . Fins
b. Stabilizers (horizontal or vertical).
(1) Size.
(2) Shape.
(3) Location.
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, ..
,,. ...
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17. Air ducts.
a. Slots.
b. Duct openings.
18. Speed - M.P.H.
19. Sound.
a. Continuous whine or buzz.
b. Roar, whistle, whoosh.
c. Intermittent.
20. Manner of disappearance.
a.
Explode.
(1) Possibility of fragments.
(2) Other physical evidence.
b. Faded from view.
c. Disappeared behind obstacle.
Relative to the Observer
1. Name of observer.
2. Address.
3. Occupation.
4. Place of business.
a. Employer or employee.
5. Pertinent hobbies.
a. Is observer amateur astronomer, pilot, engineer, etc.
b. Length of time engaged in hobby (experience).
6. AbUity to determine:
a. Color.
b. Speed of moving objects.
c . Size at distance.
7. Reliability of observer.
a.
Sources.
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(1) Neighbors.
(2)
Police Dept.
(3)
FBI records.
(4)
Employer.
8. Notes relative to observer on:
a. Sightings in general.
b. How attention was drawn to object(s).
(1) Sound.
(2)
Motion.
(3) Glint of light.
c. Degree of fatigue and duration of flight at time of sighting in cases where observer is
airborne.
9. Witnesses.
a. Addressees.
b. Occupation.
C. Reliability.
10. Comments of interrogator regarding the intell1gence and character of person interrogated.
Relative to Radar Sightings
1. Re radars operating on ground.
a. Observations of range, speed, altitude and size of target.
b. Did target executive any turns?
If so, what angle (180°), etc. and what radius of turn.
If radius of turn is not observable, how long did the target stay in the turn and what was its speed?
c. Note particularly any separation of distant target into several targets upon approach. Track
all if possible.
2.
If airborne when object sighted.
a. Were there any radar inductions or extra noise on radio circuits?
b. Give estimates of size, speed, maneuvers, etc.
GENERAL
1. Teletype sequences of local weather conditions.
2. Winds aloft report.
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3. Local flight schedules of commercial, private and military aircraft flying in vic!nity at the
time.
(Check Canadian activity if close to that border.)
4. Possible releases of testing devices in vicinity sent aloft by Ordnance, Navy, Air Force,
Army, Weather Units, Research Organizations or any other.
5.
Jf object contacted earth, obtain soil samples within and without depression or spot where
object landed (and then presumably departed) for purpose of making comparison of soils.
6.
Jf object came sufficiently near other aircraft or known objects check surfaces with Geiger
counters for possible radioactivity. Make comparisons with other unaffected aircraft objects, etc.
7. Obtain photographs (or original negatives) where available; if not, secure sketches of:
a. Object.
b. Surrounding terrain where observed.
c. Place where it contacted earth (ii this happened).
d. Maneuvers.
e. Formation ii objects were more than two.
8. Secure signed statement.
9. Obtain fragments or physical evidence where possible.
10. Was any radio antenna to be observed, i.e., (any projections or extentlons that might presum­
ably be construed as such).
c>:1-?~
C. P . CABELL
Major General, USAF
Director of Intelligence, Office of
Deputy Chief of Staff, Operations
DISTRIBUTION:
Commanding Generals, Major Air Commands,
ZI and Overseas
All United States Air Attaches
Director of Central Intelligence
Special Assistant for Research and Intelligence,
Department of State
Director of Intelligence, GSUSA
Chief of Naval Intelligence
Commandant (INT), United States Coast Guard
Director, Federal Bureau of Investigation
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DEPARTMENT OF THE AIR FORCE
HEADQUARTERS UNITED STATES AIR FORCE
DIRECTORATE OF INTELLIGENCE
WASHINGTON 25, D. C.
15 February 1949
AIR INTELLIGENCE REQUIREMENTS
MEMORANDUM NUMBER 4
UNCONVENTIONAL AIRCRAFT
PART I - GENERAL
1. PURPOSE
The purpose of this memorandum is twofold:
a. To enunciate continuing Air Force requirements for information pertaining to sightings of
unconventional aircraft and unidentified flying objects, including the so-called "Flying Discs."
b. To establlsh procedures for reporting such information.
2. RESCISSION
Department of the Army Collection Memorandum Number 7, dated 21 January 1948, and letter,
CSGID 425.1, dated 25 March 1948, both subject as above, which have been transferred to Air
Force agencies for action, ar e herewith superseded.
3. REPORTING
a. General
(1) As complete an answer to the requirements enunciated in Part II, as may be procur­
able, should be dispatched by means of electrical transmission immediately after sightings.
(2) Supplementary reports should be forwarded as available by the most expeditious means
consistent with the importance of the information reported.
b. Major Air Commands (Overseas) and Air Attaches
(1) Initial and supplementary cabled reports wlll be transmitted to the Director of Intelll­
gence, Headquarters United State:s Air Force. Cables will contain the phase, "Pass to
COMGENAMC WRIGHT-PATTERSON AFB, DAYTON, OHIO, ATTN: MCIAX0-3."
RESTRICTED
~a- 8 ~t-9~-/t'1/

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(2) Supplementary written reports, prepared on AF Form 112, will be forwarded to the
Director of Intelligence, Headquarters United States Air Force.
(3) Commanding General, Air Materiel Command is authorized direct contact with major
Air Commands (overseas) and organizations under their control in connection with the
development of information on thl.s subject.
c. Major Air Commands (ZI)
(1) Reports wlll be forwarded direct to the Commanding General, Al.r Materiel Command,
Wright-Patterson Al.r Force Base, Dayton, Ohio, Attn: MCIAXO-3 by installations receiv­
ing lnformation pertaining to the requirements enunciated in Part II.
(2) Copies of such r eports may be supplied the Command Headquarters of the installation
concerned.
(3) A copy of all r eports sent to Air Materiel Command in accordance with these instruc­
tions wlll be forwarded at the same ti.me to the Director of Intelligence, Headquarters
United States Air Force.
(4) Written r eports will be submitted on AF Form 112.
(5) Commanding General, Air Materiel Command is authorized direct contact with major
Air Commands (ZI) and organizations under thel.r control in connection wl.th the develop­
ment of information on this subject.
d. Non-Air Force Agencies
(1) Addressees otQer than those of the United States Air Force are r equested to forward
r eports direct to the Commanding General, Al.r Materiel Command, Wright-Patterson Air
Force Base, Dayton, Ohio, Attn: MCIAXO-3.
(2) In order to r educe the ti.me factor involved in transmission of this type of information
it is r equested that, wher ever communications facilities permit, subordinate elements be
authorized to communicate reports dir ect to the Commanding General, Air Materiel Com­
mand.
PART Il - REQUIREMENTS
General
1. Date of sighting.
2. Time of sighting (zonal by 24 hr. clock).
3. Where sighted (observer's position):
a. Ground
(1) City, town.
(2)
Distance and direction from city or town, road, intersection, etc.
(3)
Fr om building (story), yard, etc.
(4) Map coordinates (lf feasible) showing latitude and longitude.
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RESTRIC:t'ED
b.
Air
(1)
Type aircraft, speed, altltude, direction of flight.
(2) Distance and direction from city, town or known landmark.
(3)
Clock position of object from observer's aircraft.
(4) Latitude and longitude.
c. Sea
(1) Latitude and longitude.
(2)
Proximity to land.
(Name city, country, etc.)
4.
Number of objects.
Formation type (l.f any), sketch l.f possible.
5. Observable celestial phenomena or planets that may account for the slghtlng.
(Local fac111t!.es
or organizations which follow such celestial phenomena should be consulted for such information.)
6. Distance of object from observer.
a.
Laterally or horizontally.
b. Angle of elevation from horizon.
c. Altitude.
7.
Time in sight.
8. Appearance of object.
a. Color.
b. Shape.
(Sketch ti possible)
c. Apparent construction.
(Of what material or substance)
d. Size.
(1)
Estimated size.
(2) Size as Lt appeared from observer's view. (Compared to known object)
Q.
Direction of flight.
10. Tactics or maneuvers.
Vertical ascent or descent, horizontal, osctllatlng, fluttering, evasive, aggressive, erratic, etc.
11. Evidence of exhaust.
a. Color of smoke.
, b. Length and width.
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c. Odor (if any).
d. Rate of evaporatlon.
e. Does trail vary with sound?
(spurts)
12. Effect on clouds.
a.
Opened path thru clouds.
b.
Forced cloud or mists.
c. Reflected on cloud.
d. Showed thru cloud.
13. Lights.
a. Reflected or attached.
b.
Luminous
c. Blinked on and off in r elation to speed.
14. Support
a. Wings.
b. Aerodynamic list of fuselage.
c. Vertical jet.
d. Rotating cylinder or cone.
e. Aerostatic lift (balloon or dirigible).
15. Propulsion.
a. Propeller or jet .
b.
Rotor .
c. Aerodynamlc vanes (flapping or osclllating) (Katz Mayer effect).
d. Visible exhaust or jet openings.
16. Control artd stability.
a. Fins
b. Stablll.zers (hor izontal or vertical).
(1) Size.
(2) Shape.
(3) Location.
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17. Al.r ducts.
a. Slots.
b. Duct openings.
18. Speed - M.P.H.
19. Sound.
a. Continuous wblne or buzz.
b. Roar, whistle, whoosh.
c. Interml.ttent.
20. Manner of disappearance.
a. Explode.
(1)
Possl.bill.ty of fragments.
(2)
Other physl.cal evldence.
b.
Faded from vlew.
c. Disappeared behlnd obstacle.
Relative to the Observer
1. Name of observer.
2. Address.
3. Occupation.
4. Place of business.
a. Employer or employee.
5. Pertinent hobbles.
a. Is observer amateur astronomer, pllot, engineer, etc.
b. Length of time engaged in hobby (experience).
6. Abllity to determine:
a. Color.
b. Speed of movl.ng objects.
c. Size at distance.
? . ReUabll1ty of observer.
a.
Sources.
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(1) Neighbors.
(2) Police Dept.
(3) FBI records .
(4)
Employer.
8. Notes relative to observer on:
a. Sightings in general.
b. How attention was drawn to object(s).
(1) Sound.
(2) Motion.
(3) Glint of llght.
c. Degree of fatigue and duratlon of flight at time of sighting in cases where observer ls
airborne.
9. Witnesses.
a. Addressees.
b.
Occupation.
c. Reliabllity.
10. Comments of interrogator regarding the intelligence and character of person interrogated.
Relative to Radar Sightings
1. Re radars operating on ground.
a. Observations of range, speed, altitude and size of target.
b.
Did target executive any turns? If so, what angle (180°), etc. and what radius of turn.
If radius of turn 1s not observable, how long did the target stay in the turn and what was its speed?
c. Note particularly any separation of distant target into several targets upon approach. Track
all if possible.
2. If airborne when object sighted.
a. Were there any radar inductions or extra noise on radio circuits?
b. Give estimates of size, speed, maneuvers, etc.
GENERAL
1. Teletype sequences of local weather condltl.ons.
2. Winds aloft report.
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3. Local fUght schedules of commercial, private and m1litary aircraft flying in vicinity at the
time.
(Check Canadian activ1ty 1f close to that border.)
4. Possible releases of testing devices ln vicinity sent aloft by Ordnance, Navy, Air Force,
Army, Weather Units, Research Organizations or any other.
6. If object contacted earth, obtain soil samples within and without depression or spot where
object landed (and then presumably departed) for purpose of making comparison of sons.
6. If object came sufficiently near other aircraft or known objects check surfaces with Geiger
counters for possible radioactivity. Make comparisons with other unaffected aircraft objects, etc.
7. Obtain photographs (or original negatives) where available; if not, secure sketches of:
a. Object.
b. Surrounding terrain where observed.
c. Place where it contacted earth (if this happened).
d. Maneuvers.
e. Formation if objects were more than two.
8. Secure signed statement.
9. Obtain fragments or physical evidence where possible.
10. Was any radio antenna to be observed, 1.e., (any projections or extentions that might presum­
ably be construed as such).
c>:t-!~
C. P. CABELL
Major General, USAF
Director of Intelligence, Offlce of
Deputy Chtef of Staff, Operations
DISTRlBUTION:
Commanding Generals, Major Air Commands,
ZI and Overseas
All United States Air Attaches
Director of Central Intelligence
Special Assistant for Research and Intelllgence,
Department of State
Director of Intelligence, GSUSA
Chief of Naval Intelligence
Commandant (INT), United States Coast Guard
DirectorI Federal Bur eau of Investigation
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DEPARTMENI' OF THE Affi. FORCE
HEADQUARTERS UNITED STATES Am FORCE
DmECTORATE OF INI'ELLIGENCE
WASHINGTON 25, D. C.
15 February 1949
Am INTELLIGENCE REQUIBEMENI'S
MEMORANDUM NUMBER 4
UNCONVENTIONAL Arn.CRAFT
PART I - GENERAL
1. PURPOSE
The purpose of this memorandum ls twofold;
a.
To enunciate continuing Air Force requirements for information pertaining to sightings of
unconventional aircraft and un1dent1f1ed flying objects, including the so-called "Flying Discs. "
b. To establish procedures for reporting such information.
2. RESCISSION
Department of the Army Collection Memorandum Number 7, dated 21 January 1948, and letter,
CSGID 425.1, dated 25 March 1948, both subject as above, which have been transferred to Air
Force agencies for action, are herewith superseded.
3. REPORTING
a.
General
(1)
As complete an answer to the requirements enunciated in Part II, as may be procur­
able, should be dispatched by means of electrical transmission immediately after sightings.
(2)
Supplementary reports should be forwarded as available by the most expeditlous means
consistent with the importance of the information reported.
b. Major Air Commands (Overseas) and Air Attaches
(1) Initial and supplementary cabled reports will be transmitted to the Director of Intem­
gence, Headquarters United State:s Air Force.
Cables will contain the phase, "Pass to
COMGENAMC WRIGHT-PATTERSON AFB, DAYTON, OHIO, ATTN: MCIAX0-3."
RESTRICTED

RESTRICTED
(2) Supplementary written reports, prepared on AF Form 112, wlll be forwarded to the
Director of Intelllgence, Headquarters United States Air Force.
(3)
Commanding General, Air Materiel Command is authorized direct contact with major
Al.r Commands (overseas) and organizations under their control in connection with the
development of information on this subject.
c. Major Air Commands (Zl)
(1) Reports will be forwarded direct to the Commanding General, Air Materiel Command,
Wright-Patterson Air Force Base, Dayton, Ohio, Attn: MCIAXO-3 by l.nstallations receiv­
ing information pertaining to the requirements enunciated in Part TI.
(2) Copies of such reports may be supplied the Command Headquarters of the installation
concerned.
(3)
A copy of all reports sent to Air Materiel Command in accordance with these instruc­
tions will be forwarded at the same time to the Dlrector of Intelligence, Headquarters
United States Air Force.
(4) Written r eports wlll be submitted on AF Form 112.
(5) Commanding General, Al.r Materiel Command is authorized direct contact with major
Air Commands (ZI) and organizations under their control in connection with the develop­
ment of information on this subject.
d. Non-Air Force Agencies
(1) Addressees otQer than those of the United states Air Force are r equested to forward
reports direct to the Commanding General, Air Materiel Command, Wright-Patter son Air
Force Base, Dayton, Ohio, Attn: MCIAXO-3.
(2) In order to reduce the time factor involved in transmission of this type of information
it ts r equested that, wher ever communications facillties permit, subordinate elements be
authorized to communicate r eports direct to the Commanding General, Air Materiel Com­
mand.
PART II - REQUIREMENTS
General
1. Date of sighting.
2.
Time of sighting (zonal by 24 hr. clock).
3. Where sighted (observer's position):
a.
Ground
(1) City, town.
(2) Distance and direction from city or town, road, intersection, etc.
(3) From building (story), yard, etc.
(4) Map coordinates (if feasible) showing latitude and l~ngitude.
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b. Air
(1) Type aircraft, speed, altitude, direction of flight.
(2) Distance and direction from city, town or known landmark.
(3) Clock position of object from observer's aircraft.
(4) Latitude and longitude.
c. Sea
(1) Latitude and longitude.
(2) Proximity to land.
(Name city, country, etc.)
4. Number of objects.
Formation type (if any), sketch if possible.
5. Observable celestial phenomena or planets that may account for the sighting.
(Local facilities
or organizations which follow such celestial phenomena should be consulted for such information.)
6. Distance of object from observer.
a. Laterally or horizontally.
b. Angle of elevation from horizon.
c. Altitude.
7. Time in sight.
8.
Appearance of object.
a. Color.
b. Shape.
(Sketch if possible)
c. Apparent construction.
(Of what material or substance)
d. Size.
(1) Estimated size.
(2) Size as it appeared from observer's view. (Compared to known object)
9. Direction of flight.
10. Tactics or maneuvers.
Vertical ascent or descent, horizontal, osclllating, fluttering, evasive, aggressive, erratic, etc.
11. Evidence of exhaust.
a. Color of smoke.
, b. Length and width.
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•

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c. Odor (if any).
d. Rate of evaporation.
e. Does trail vary with sound?
(spurts)
12. Effect on clouds.
a. Opened path thru clouds.
b. Forced cloud or mists .
c. Reflected on cloud.
d. Showed thru cloud.
13, Lights.
a.
Reflected or attached.
b. Luminous
c. Blinked on and off Ln r elation to speed.
14. Support
a. Wings.
b. Aerodynamic list of fuselage.
c. Vertical jet.
d. Rotating cylinder or cone.
e. Aerostatic lift (balloon or dirigible).
15.
Propulsion.
a. Pr opeller or jet.
b. Rotor.
c. Aerodynamic vanes (flapping or oscillating) (Katz Mayer effect).
d. Visible exhaust or jet openings.
16. Control and stability.
a. Fins
b. StabiUzers (hor izontal or vertical).
(1) Size.
(2) Shape.
(3)
Location.
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17. Alr ducts.
a. Slots.
b. Duct openlngs.
18. Speed - M.P.H.
19. Sound.
a. Continuous whlne or buzz.
b. Roar, whlstle, wl;loosh.
c. Intermittent.
20. Manner of disappearance.
a. Explode.
(1)
PosslbHlty of fragments.
(2)
Other physical evidence.
b. Faded from view.
c. Disappeared behind obstacle.
Relative to the Observer
1. Name of observer.
2. Address.
3. Occupation.
4. Place of business.
a. Employer or employee.
5. Pertinent hobbies.
a. Is observer amateur astronomer, pilot, engineer, etc.
b. Length of time engaged ln hobby (experience).
6. Ablllty to determine:
a . Color.
b. Speed of moving objects.
c. Size at distance.
7. Rell.abllity of observer.
a. Sources.
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(1) Neighbors.
(2) Police Dept.
(3) FBI records.
(4) Employer.
8. Notes relative to observer on:
a. Sightings in general.
b. How attention was drawn to ob1ect(s).
(1) Sound.
(2) Motion.
(3) Glint of light,
c. Degree of fatigue and duration of :flight at time of sighting in cases where observer is
airborne.
9. Witnesses.
a. Addressees.
b. Occupation.
c. Reliability.
10. Comments of interrogator regarding the intelHgence and character of person interrogated.
Relative to Radar Sightings
1. Re radars operating on ground.
a. Observatlons of range, speed, altitude and size of target.
b. Did target executive any turns? If so, what arlgle (180°), etc. and what radius of turn.
If radius of turn is not observable, how long did the target stay 1n the turn and what was its speed?
c. Note particularly any separation of distant target into several targets upon approach. Track
all if possible.
2.
If airborne when object sighted.
a. Were there any radar inductions or extra noise on radio circuits?
b. Give estimates of size, speed, maneuvers, etc.
GENERAL
1. Teletype sequences of local weather conditions.
2.
Winds aloft report.
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..
RESTR I CTED
3, Local flight schedules of commercial, private and m111tary aircraft flying in vicinity at the
time. {Check Canadian activity if close to that border.)
4. Possible releases of testing devices in vicinity sent aloft by Ordnance, Navy, Alr Force,
Army, Weather Units, Research Organizations or any other.
6. If object contacted earth, obtain sou samples within and without depression or spot where
object landed {and then presumably departed) for purpose of making comparison of sol.ls.
6.
If object came sufficiently near other aircraft or known objects check surfaces with Geiger
counters for possible radioactivity. Make comparisons with other unaffected aircraft objects, etc.
7. Obtain photographs {or original negatives) where available; if not, secure sketches of:
a. Object.
b. Surrounding terrain where observed.
c. Place where it contacted earth (if this happened).
d. Maneuvers.
e. Formation if objects were more than two.
8. Secure signed statement.
9.
Obtain fragments or physical evidence where possible.
10. Was any radio antenna to be observed, l..e., {any projections or extentlons that mlght presum­
ably be construed as such).
cl?~
C. P. CABELL
Major General, USAF
Director of Intelligence, Office of
Deputy Chief of Staff, Operations
DISTRIBUTION:
Commanding Generals, Major Air Commands,
ZI and Overseas
All United States Air Attaches
Director of Central Intelligence
Special Assistant for Research and IntelUgence,
Department of State
Director of Intelligence, GSUSA
Chief of Naval Intelligence
Commandant (INT), United States Coast Guard
Director, Federal Bureau of Investlgatlon
RESTRIC TED
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RESTRICTED

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DEPARTMENT OF THE Affi FORCE
HEADQUARTERS UNITED STATES AIR FORCE
DlRECTORATE OF INTELLIGENCE
WASHINGTON 25, D. C.
16 February 1949
AIR INTELLIGENCE REQUIREMENTS
MEMORANDUM NUMBER 4
UNCONVENTIONAL AJRCRAFT
PART I - GENERAL
1. PURPOSE
The purpose of this memorandum is twofold:
a. To enunciate continuing Air Force requirements for information pertaining to sightings of
unconventional aircraft and unidentified flying objects, including the so-called "Flying Discs."
b. To establish procedures for reporting such information.
2. RESCISSION
Department of the Army Collection Memorandum Number 7, dated 21 January 1948, and letter,
CSGID 425.1, dated 25 March 1948, both subject as above, which have been transfer red to Air
Force agencies for action, are herewith superseded.
3. REPORTING
a. General
(1)
As complete an answer to the requirements enunciated in Part II, as may be procur­
able, should be dispatched by means of electrical transmission immediately after sightings.
(2) Supplementary reports should be forwarded as available by the most expeditious means
consistent with the importance of the information reported.
b. Major Air Commands (Overseas) and Air Attaches
(1) Initial and supplementary cabled reports wlll be transmitted to the Dir ector of Intelli­
gence, Headquarters United State:s Air Force. Cables will contain the phase, " Pass to
COMGENAMC WRIGHT-PATTERSON AFB, DAYTON, OHIO, ATTN: MCIAX0-3."
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C9-H92, AF

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(2) Supplementary written reports, prepared on AF Form 112, will be forwarded to the
Director of Intelll.gence, Headquarters Unlted States Alr Force.
(3) Commandlng General, Air Materiel Command is authorized direct contact with major
Alr Commands (overseas) and organizations under thelr control in connection with the
development of information on this subject.
c. Major Air Commands (ZI)
(1) Reports will be forwarded dlrect to the Commanding General, Air Materiel Command,
Wright-Patterson Air Force Base, Dayton, Ohio, Attn: MCIAXO-3 by installatlons r eceiv­
ing information pertaining to the requirements enunciated ln P art II.
(2) Coples of such r eports may be supplied the Command Headquarters of the installation
concerned.
(3) A copy of all reports sent to Air Materiel Command in accordance with these instruc­
tions will be forwarded at the same time to the Director of Intelllgence, Headquarters
United States Air Force.
(4) Written r eports will be submitted on AF Form 112.
(5) Commandlng General, Air Materiel Command is authorized direct contact with major
Air Commands (ZI) and organizations under their control in connection with the develop­
ment of information on this subject.
d. Non-Air Force Agencies
(1) Addressees otQer than those of the United States Air Force are requested to forward
r eports direct to the Commanding General, Air Materiel Command, Wright-Patterson Air
Force Base, Dayton, Ohio, Attn: MCIAXO-3.
(2) In order to reduce the time factor involved ln transmission of this type of information
it is r equested that, wher ever communications facilltles permit, subordinate elements be
authorized to communicate r eports direct to the Commanding General, Air Materiel Com­
mand.
PART II - REQUIREMENTS
General
1. Date of sighting.
2. Time of sighting (zonal by 24 hr. clock).
3. Where sighted (observer's posltion):
a. Ground
(1) City, town.
(2) Distance and direction from city or town, road, lnter sect1on, etc.
(3) From building (story), yard, etc.
(4) Map coordinates (if feasible) showing latitude and longitude.
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b. Air
(1)
Type aircraft, speed, altitude, direction of flight.
(2)
Distance and direction from city, town or known landmark.
(3)
Clock position of object from observer's aircraft.
(4) Latitude and longitude.
c. Sea
(1) Latitude and longitude.
(2) Proxlmity to land.
(Name city, country, etc.)
4,
Number of objects.
Formation type (if any), sketch 1f possible.
6. Observable celestial phenomena or planets that may account for the slghtlng.
(Local facillties
or organizations which follow such celestial phenomena should be consulted for such information.)
6. Distance of object from observer.
a. Laterally or horizontally.
b. Angle of elevation from horizon.
c. Altitude.
7. Time in sight.
8.
Appearance of object.
a. Color.
b. Shape.
(Sketch if possible)
c. Apparent construction.
(Of what material or substance)
d. Size.
(l} Estimated size.
(2) Size as Lt appeared from observer's view. (Compared to known object)
9. Direction of flight,
10. Tactics or maneuvers.
Vertical ascent or descent, horizontal, osclllatlng, flutterlng, evasive, aggressive, erratic, etc.
11. Evidence of exhaust.
a. Color of smoke.
, b. Length and width.
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C.
Odor (if any).
d.
Rate of evaporation.
e.
Does trail vary wlth sound? (spurts)
12, Effect on clouds.
a.
Opened path thru clouds.
b.
Forced cloud or mists.
c.
Reflected on cloud.
d. Showed thru cloud.
13. Lights.
a. Reflected or attached.
b. Luminous
c.
Blinked on and off in relation to speed.
14. Support
a. Wings.
b.
Aerodynamic 11st of fuselage.
C .
Vertical jet.
d.
Rotating cylinder or cone.
e.
Aerostatic lift (balloon or dir igible).
15. Pr opulslon.
a.
Propeller or jet.
b.
Rotor.
c.
Aerodynamlc vanes (flapping or osclilating) (Katz Mayer effect).
d. Visible eXhaust or jet openings.
16. Control and stability.
a.
Fins
b. Stabilizers (horizontal or vertical).
(1) Size.
(2) Shape.
(3) Location.
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17. Air ducts.
a. Slots.
b. Duct openings.
18. Speed - M.P.H.
19. Sound.
a. Continuous whine or buzz.
b, Roar, whistle, whoosh.
c. Intermittent.
20.
Manner of disappearance.
a. Explode.
(1) Possibility of fragments.
(2) Other physical evidence.
b. Faded from view.
c. Disappeared behind obstacle.
Relative to the Observer
1.
Name of observer.
2. Address.
3.
Occupation.
4. Place of business.
a. Employer or employee.
5. Pertinent hobbies.
a. Is observer amateur astronomer, pilot, engineer, etc.
b. Length of time engaged in hobby (experience).
6.
Ability to determine:
a. Color,
b. Speed of moving objects.
c . Size at distance.
7.
Reliability of observer.
a.
Sources.
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- 5 ­

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(1) Neighbors.
(2) Police Dept.
(3) FBI records.
(4) Employer.
8. Notes relative to observer on:
a. Sightings in general.
b. How attention was drawn to object{s).
(1) Sound.
(2) Motion.
(3) Glint of light.
c. Degree of fatigue and duration of flight at time of sighting ln cases where observer ls
airborne.
9. Witnesses.
a. Addressees.
b. Occupation.
c. Reliability.
10. Comments of interrogator regarding the intelligence and character of person interrogated.
Relative to Radar Sightings
1. Re radars operating on ground.
a. Observations of range, speed, altitude and size of target.
b.
Did target executive any turns? If so, what angle (180°), etc. and what radius of turn.
If radius of turn ls not observable, how long did the target stay in the turn and what was its speed?
c. Note particularly any separation of distant target into several targets upon approach. Track
all 1f possible.
2. If airborne when object sighted.
a. Were there any radar inductions or extra noise on radio circuits?
b. Give estimates of size, speed, maneuvers, etc.
GENERAL
1. Teletype sequences of local weather conditions.
2. Winds aloft r eport.
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3. Local flight schedules of commerc1al, private and m1Utary aircraft flying ln viclnity at the
time.
(Check Canadian activity if close to that border.)
4. Possible releases of testlng devices in vicinity sent aloft by Ordnance, Navy, Air Force,
Army, Weather Units, Research Organizations or any other.
5. If object contacted earth, obtain son samples within and without depression or spot where
object landed (and then presumably departed) for purpose of making comparison of soils.
6. If object came sufficiently near other aircraft or known objects check surfaces with Geiger
counters for possible radioactivity. Make comparisons with other unaffected aircraft objects, etc.
7. Obtain photographs (or original negatives) where available; if not, secure sketches of:
a. Object.
b. Surrounding terraln where observed.
c. Place where 1t contacted earth (if this happened).
d. Maneuvers.
e. Formation if objects were more than two.
8. Secure signed statement.
9. Obtain fragments or physical evidence where possible.
10. Was any radio antenna to be observed, i.e., (any projections or extentlons that might presum­
ably be construed as such).
cl-!~
C. P. CABELL
Major General, USAF
Director of Intelligence, Office of
Deputy Chief of Staff, Operations
DISTRJBUTION:
Commanding Generals, Major Air Commands,
ZI and Overseas
All United States Air Attaches
Director of Central Intelligence
Special Assistant for Research and Intelllgence,
Department of State
Director of Intelllgence, GSUSA
Chief of Naval Intelligence
Commandant (INT), United States Coast Guard
Director, Federal Bureau of Investigation
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RESTRICTED

RESTRICTED
DEPARTMENT OF THE AIR FORCE
HEADQUARTERS UNITED STATES AIR FORCE
DIRECTORATE OF INTELLIGENCE
WASHINGTON 25, D. C.
15 February 1949
Am INTELLIGENCE REQUIB.EMENTS
MEMORANDUM NUMBER 4
UNCONVENTIONAL AIRCRAFT
PART I - GENERAL
1.
PURPOSE
The purpose of this memorandum is twofold:
a. To enunciate continuing Air Force requirements for information pertaining to s ightings of
unconventional aircraft and unidentified flying objects, including the so-called "Flying Discs."
b. To establish procedures for reporting such information.
2. RESCISSION
Department of the Army Collection Memorandum Number 7, dated 21 January 1948, and letter,
CSGID 425.1, dated 25 March 1948, both subject as above, which have been transferred to Air
Force agencies for action, are herewith superseded.
3. REPORTING
a.
General
(1) As complete an answer to the requirements enWlCiated in Part II, as may be procur­
able, should be dispatched by means of electrical transmission immediately after sightings.
(2) Supplementary reports should be forwarded as available by the most expeditious means
consistent with the importance of the information reported.
b. Major Air Commands (Overseas) and Air Attaches
(1) Initial and supplementary cabled reports will be transmitted to the Director of IntelU­
gence, Headquarters United States Air Force. Cables wm contain the phase, "Pass to
COMGENAMC WRIGHT-PATTERSON AFB, DAYTON, OHIO, ATTN:
MCIAX0-3."
RESTRICTED
C9-'892,AF

RESTRICTED
(2) Supplementary written reports, prepared on AF Form 112, will be forwarded to the
Director of Intelligence, Headquarters United States Alr Force.
(3) Commandlng General, Alr Materiel Command ls authorized direct contact with major
Air Commands (over seas) and organizations under their control in connection with the
development of information on this subject.
c. Major Air Commands (ZI)
(1) Reports wlll be forwarded direct to the Commanding General, Air Materiel Command,
Wright-Patterson Air Force Base, Dayton, Ohio, Attn:
MCIAX0-3 by Installations r eceiv­
ing information pertaining to the requirements enunciated in Part II.
(2) Copies of such r eports may be supplied the Command Headquarters of the installation
concerned.
(3) A copy of all reports sent to Air Materiel Command in accordance with these instruc­
tions wtll be forwarded at the same time to the Director of Intelligence, Headquarters
United states Air Force.
(4) Written r eports wm be submitted on AF Form 112.
(5) Commanding General, Air Materiel Command ls authorized direct contact with major
Air Commands (ZI) and or ganizations under their control in connection with the develop­
ment of information on this subject.
d. Non-Air Force Agencies
(1) Addr essees ot.cyer than those of the United states Air For ce are requested to forward
reports direct to the Commanding General, Air Materiel Command, Wright-Patterson Air
Force Base, Dayton, Ohio, Attn: MCIAX0-3.
(2) In order to reduce the time factor involved in transmission of this type of information
it is requested that, wher ever communications faciUties permit, subordinate elements be
authorized to communicate r eports direct to the Commanding General, Air Materiel Com­
mand.
PART IT - REQUIREMENTS
General
1. Date of sighting.
2. Time of sighting (zonal by 24 hr. clock).
3. Where sighted (observer's position):
a. Ground
(1) City, town.
(2)
Distance and direction from city or town, r oad, inter section, etc.
(3)
From building (story), yard, etc.
(4) Map coordinates (if feasible) showing latitude and longitude.
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b. Air
(1) Type aircraft, speed, altitude, direction of flight.
(2) Distance and direction from city, town or known landmark.
(3) Clock position of object from observer's aircraft.
(4) Latitude and longitude.
c. Sea
(1) Latitude and longitude.
(2) Proxlmity to land. (Name city, country, etc.)
4.
Number of objects.
Formation type (If any), sketch if possible.
5. Observable celestial phenomena or planets that may account for the sighting.
(Local facilities
or organizations which follow such celestial phenomena should be consulted for such information.)
6.
Distance of object from observer.
a. Laterally or horizontally.
b. Angle of elevation from horizon.
c. Altitude.
7. Time in sight.
8. Appearance of object.
a. Color.
b. Shape.
(Sketch if possible)
c. Apparent construction.
(Of what material or substance)
d. Size.
(1)
Estimated size.
(2) Size as it appeared from observer's view. (Compared to known object)
9. Direction of fllght.
10. Tactics or maneuvers.
Vertical ascent or descent, horizontal, oscillating, fluttering, evasive, aggressive, erratic, etc.
11.
Evidence of exhaust.
a. Color of smoke.
, b. Length and width.
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- 3 -
•

RESTRICTED
C.
Odor (if any).
d. Rate of evaporation.
e. Does trall vary with sound?
(spurts)
12. Effect on clouds.
a . Opened path thru clouds.
b. Forced cloud or mists.
c. Reflected on cloud.
d. Showed thru cloud.
13. Lights.
a. Reflected or attached.
b. Luminous
c. Blinked on and off ln relation to speed.
14. Support
a. Wings.
b. Aerodynamic Hst of fuselage.
c. Vertical jet.
d. Rotating cylinder or cone.
e. Aerostatic 11.ft (balloon or dirigible).
15. Propulsion.
a. Propeller or jet.
b. Rotor.
c. Aerodynamic vanes (flapping or osc1llat1ng) (Katz Mayer effect).
d. Visible exhaust or jet openings.
16. Control and stabHity.
a. Fins
b. Stabil!.zers (horizontal or vertical).
(1) Size.
(2) Shape.
(3) Location.
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RESTR ICTED
17. Air ducts.
a. Slots.
b. Duct openings.
18. Speed - M.P.H.
19. Sound.
a. Continuous whine or buzz.
b. Roar, whistle, w};loosh.
c. Intermittent.
20. Manner of disappearance.
a.
Explode.
(1) Poss1b1Uty of fragments.
(2)
Other physical evidence.
b. Faded from view.
c. Disappeared behind obstacle.
Relattve to the Observer
1. Name of observer.
2. Address.
3. Occupation.
4.
Place of business.
a. Employer or employee.
6.
Pertinent hobbies.
a. Is observer amateur astronomer, pilot, engineer, etc.
b. Length of time engaged in hobby (experience).
6.
Ability to determine:
a. Color.
b. Speed of moving objects.
c. Size at distance.
7. Reliablllty of observer.
a. Sources.
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(1) Neighbors.
(2) Pollce Dept.
(3) FBI records.
(4) Employer.
8. Notes relative to observer on:
a. Sightings in gener al.
b. How attention was drawn to object(s).
(1) Sound.
(2) Motion.
(3) Glint of light.
c. Degree of fatigue and duration of flight at time of sighting in cases where observer is
airborne.
9. Witnesses.
a. Addressees.
b. Occupation.
c. Rellablllty.
10. Comments of interrogator regarding the lntelllgence and character of person interrogated.
Relative to Radar Sightings
1. Re radars operating on ground.
a. Observations of range, speed, altitude and size of target.
b. Did target executive any turns? If so, what angle (180°), etc. and what radius of turn.
If radius of turn is not observable, how long did the target stay ln the turn and what was its speed?
c. Note particularly any separation of distant target into several targets upon approach. Tr ack
all l.f possible.
2. If airborne when object sighted.
a. Were there any radar inductions or extra noise on radio circuits?
b. Give estimates of size, speed, maneuvers, etc.
GENERAL
1. Teletype sequences of local weather conditions.
2. Winds aloft report.
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3. Local fllght schedules of commercial, private and mll1tary aircraft flying in vidnlty at the
time.
(Check Canadian activity l.f close to that border.)
4. Possible releases of testing devices in vlcinlty sent aloft by Ordnance, Navy, Air Force,
Army, Weather Units, Research Organizations or any other.
5.
If object contacted earth, obtain soil samples within and without depression or spot where
object landed (and then presumably departed) for purpose of making comparison of soils.
6. If object came sufficiently near other aircraft or known objects check surfaces with Gelger
counters for possible radioactivity. Make comparisons with other unaffected aircraft objects, etc.
7. Obtain photographs (or original negatives) where available; if not, secure sketches of:
a. Object.
b. Surrounding terrain where observed.
c. Place where 1t contacted earth (if this happened).
d. Maneuvers.
e. Formation if objects were more than two.
8. Secure signed statement.
9.
Obtain fragments or physical evidence where possible.
10. Was any radio antenna to be observed, Le., (any projections or extentlons that might presum­
ably be construed as such).
e>:P~
C. P. CABELL
Major General, USAF
Dlrector of Intelligence, Office of
Deputy Chief of Staff, Operations
DISTRlBUTION:
Commanding Generals, Major Air Commands,
ZI and Overseas
All United States Air Attaches
Director of Central lntelllgence
Special Assistant for Research and Intelligence,
Department of State
Director of Intelligence, GSUSA
Chief of Naval Intelligence
Commandant (INT), United States Coast Guard
Director , Federal Bureau of Invest1gatlon
RESTRICTED
- 7 -

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RESTRICTED
DEPARTMENT OF THE AIR FORCE
HEADQUARTERS UNITED STATES AIR FORCE
DIRECTORATE OF INTELLIGENCE
WASHINGTON 25, D. C.
15 February 1949
AIR INTELLIGENCE REQUIREMENTS
MEMORANDUM NUMBER 4
UNCONVENTIONAL AIRCRAFT
PART I - GENERAL
1. PURPOSE
The purpose of this memorandum is twofold:
a. To enunciate continuing Air Force requirements for information pertalning to sightings of
unconventional aircraft and unidentified flying objects, including the so-called "Flying Discs."
b. To establish procedures for reporting such information.
2. RESCISSION
Department of the Army Collection Memorandum Number 7, dated 21 January 1948, and letter,
CSGID 425.1, dated 25 March 1948, both subject as above, which have been transferred to Air
Force agencies for action, are herewith superseded.
3. REPORTING
a. General
(1)
As complete an answer to the requirements enunciated 1n Part II, as may be procur ­
able, should be dispatched by means of electrical transmission immediately after sightings.
(2) Supplementary reports should be forwarded as available by the most expeditious means
consistent with the importance of the information reported.
b. Major Air Commands (Overseas) and Air Attaches
(1) Initial and supplementary cabled reports will be transmitted to the Director of Intelll­
gence, Headquarters United Stat(:s Air Force. Cables wl.11 contain the phase, "Pass to
COMGENAMC WRIGHT-PATTERSON AFB, DAYTON, OHIO, ATTN: MCIAX0-3."
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(2) Supplementary wrltten reports, prepared on AF For m 112, will be forwarded to the
Director of Intelligence, Headquarters United States Air Force.
(3) Commanding General, Air Materiel Command ls authorized direct contact with major
Air Commands (overseas) and organizations under their control in connection with the
development of information on this subject,
c. Major Air Commands (ZI)
(1) Reports wm be forwarded direct to the Commanding General, Air Materiel Command,
Wright-Patterson Air Force Base, Dayton, Ohio, Attn:
MCIAXO-3 by installations receiv­
ing information pertaining to the requirements enunciated in Part II.
(2) Copies of such reports may be supplied the Command Headquarters of the installation
concerned.
(3) A copy of all reports sent to Air Materiel Command in accordance with these instruc­
tions wm be forwarded at the same time to the Director of Intelligence, Headquarters
United States Air Force.
(4) Written reports will be submitted on AF Form 112.
(6) Commanding General, Air Materiel Command is authorized direct contact with major
Air Commands (ZI) and organizations under their control in connection with the develop­
ment of information on this subject.
d. Non-Air Force Agencies
(1) Addressees ot~er than those of the United States Air Force are requested to forward
reports direct to the Commanding General, Air Materiel Command, Wright-Patterson Air
Force Base, Dayton, Ohio, Attn: MCIAXO-3.
(2) In order to reduce the time factor involved in transmission of this type of information
it Ls requested that, wherever communications facilities permit, subordinate elements be
authorized to communicate reports direct to the Commanding General, Air Materiel Com­
mand.
PART II - REQUIB.EMENTS
General
1. Date of sighting.
2. Time of sightl.ng (zonal by 24 hr. clock).
3, Where sighted (observer 's position):
a. Ground
(1) City, town.
(2) Distance and direction from city or town, road, intersection, etc.
(3)
Fr om building (story), yard, etc.
(4) Map coordinates (if feasible) showing latitude and longitude.
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b. Air
(1)
Type aircraft, speed, altitude, direction of fllght.
(2) Distance and direction fr om city, town or known landmark.
(3)
Clock position of object from observer's aircraft.
(4) Latitude and longitude.
c. Sea
(1) Latitude and longitude.
(2)
Proximity to land.
(Name city, country, etc.)
4. Number of objects.
Formation type (if any), sketch if possible.
6.
Observable celestial phenomena or planets that may account for the slghtlng.
(Local fac1lities
or organizations which follow such celestial phenomena should be consulted for such information.)
6. Distance of object from observer.
a. Laterally or horizontally.
b.
Angle of elevation from horizon.
c. Altitude.
7. Time in sight.
8, Appearance of object.
a. Color.
b. Shape.
(Sketch 1f possible)
c. Apparent construction.
(Of what material or substance)
d.
Size.
(1)
Estimated size.
(2) Slze as it appeared from observer's vlew.
(Compared to known object)
9. Direction of fUght.
10. Tactics or maneuvers.
Vertical ascent or descent, horizontal, oscillatlng, fluttering,. evasive, aggressive, er ratic, etc.
11. Evidence of exhaust.
a. Color of smoke.
, b.
Length and width.
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-
3 ­

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c. Odor (if any).
d. Rate of evaporation.
e. Does trail vary with som1d?
(spurts)
12. Effect on clouds.
a. Opened path thru clouds.
b . Forced cloud or mists.
c. Reflected on cloud.
d. Showed thru cloud.
13. Llghts.
a. Reflected or attached.
b. Luminous
c. Blinked on and off in relation to speed.
14. Support
a. Wlngs.
b. Aerodynamic Ust of fuselage.
c. Vertical Jet.
d. Rotating cyllnder or cone.
e. Aerostatic lift (balloon or dir igible).
15. Propulsion.
a. Propeller or jet.
b. Rotor.
c. Aerodynamic vanes (flapping or oscillating) (Katz Mayer effect).
d. Visible exhaust or jet openings.
18. Control and stability.
a. Flns
b. Stabilizers (horizontal or vertical).
(1) Size.
(2) Shape.
(3) Location.
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17. Air ducts.
a. Slots.
b. Duct openings.
18. Speed - M.P.H.
19. Sound.
a. Continuous whine or buzz.
b. Roar, whistle, whoosh.
c. Intermittent.
20. Manner of disappearance.
a. Explode.
(1) Possibility of fragments.
(2) Other physical evidence.
b.
Faded from view.
c. Disappeared behind obstacle.
Relative to the Observer
1. Name of observer.
2. Address.
3. Occupation.
4. Place of business.
a. Employer or employee.
5. Pertinent hobbies.
a. Is observer amateur astronomer, pl.lot, engineer, etc.
b. Length of time engaged in hobby (experience).
6. Abllity to determine:
a. Color.
b. Speed of moving objects.
c. Size at distance.
7. Reliability of observer.
a.
Sources.
RESTRICTE D
- 5 -

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(1) Neighbors .
(2) Police Dept.
(3) FBI records.
(4) Employer.
8. Notes relative to observer on:
a. Sightings 1n general.
b. How attention was drawn to object(s).
(1) Sound.
(2) Motion.
(3) Glint of light.
c. Degree of fatigue and duration of flight at tlme of sightlng in cases where observer is
airborne.
9. Witnesses.
a. Addressees.
b. Occupation.
c. Reliability.
10. Comments of interrogator regarding the intelUgence and character of person interrogated.
Relative to Radar Sightings
1. Re radars operating on ground.
a. Observations of range, speed, altitude and size of target.
b. Did target executive any turns? If so, what angle (180°), etc. and what radius of turn.
If radius of turn is not observable, how long did the target stay in the turn and what was its speed?
c. Note particularly any separation of distant target into several targets upon appr oach, Track
all if possible.
2. If airborne when object sighted.
a. Were there any radar inductions or extra noise on radio circuits?
b, Give estimates of slze, speed, maneuvers, etc.
GENERAL
1. Teletype sequences of local weather conditions.
2. Winds aloft report.
- 6 -
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3. Local night schedules of commercial, private and m111tary aircraft flying 1n vicinity at the
time.
(Check Canadian activity 1f close to that border.)
4. Possible releases of testing devices 1n vicinity sent aloft by Ordnance, Navy, Alr Force,
Army, Weather Units, Research Organizations or any other.
6.
If object contacted earth, obtain soil samples within and without depression or spot where
object landed (and then presumably departed) for purpose of making comparison of soils.
6.
If object came sufficiently near other aircraft or known objects check surfaces with Geiger
counters for possible radioactivity. Make comparisons with other unaffected aircraft objects, etc.
7.
Obtain photographs (or original negatives) where available; if not, secure sketches of:
a. Object.
b. Surroundlng terrain where observed.
c. Place where it contacted earth (if this happened).
d. Maneuvers.
e. FormaUon if objects were more than two.
8. Secure signed statement.
9. Obtain fragments or physical evidence where possible.
10. Was any radio antenna to be observed, i.e., (any pr ojections or extentions that might presum­
ably be construed as such).
c:1-?~
C. P. CABELL
Major General, USAF
Director of lntell1gence, Office of
Deputy Chief of Staff, Operations
DISTRIBUTION:
Commanding Generals, Major Air Commands,
ZI and Overseas
All United States Air Attaches
Director of Central Intelligence
Special Assistant for Research and Intelligence,
Department of State
Director of Intelligence, GSUSA
Chief of Naval Intelligence
Commandant (INT), United States Coast Guard
Director, Federal Bureau of Investigation
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RESTRICTED

RESTRICTED
DEPARTMENT OF THE AIR FORCE
HEADQUARTERS UNITED STATES AIR FORCE
DIRECTORATE OF INTELLIGENCE
WASHINGTON 25, D. C.
15 February 1949
AIR INTELLIGENCE REQUIREMENTS
MEMORANDUM NUMBER 4
UNCONVENTIONAL AIRCRAFT
PART I - GENERAL
1. PURPOSE
The purpose of thls memorandum Is twofold:
a. To enunciate continuing Air Force requirements for information pertaining to sightings of
unconventional aircraft and unidentified flying objects, lncludlng the so-called "Flying Discs. 11
b. To establish procedures for reporting such information.
2. RESCISSION
Department of the Army Collection Memorandum Number 7, dated 21 January Hl48, and letter,
CSGID 425.1, dated 25 March 1948, both subject as above, which have been transferred to Air
Force agencies for action, are herewith superseded.
3. REPORTING
a.
General
(1)
As complete an answer to the requirements enunciated in Part II, as may be procur­
able, should be dispatched by means of electrical transmission immediately after sightings.
(2) Supplementary r·eports should be forwarded as available by the most expeditious means
consistent with the importance of the Information reported.
b. Major Air Commands (Overseas) and Air Attaches
(1) Initial and supplementary cabled reports will be transmitted to the Director of Intelll­
gence, Headquarters United Statc,s Air Force. Cables will contaln the phase, "Pass to
COMGENAMC WRIGHT-PATTERSON AFB, DAYTON, OHIO, ATTN: MClAX0-3."
RESTRICTED

RESTRICTED
(2) Supplementary written r eports, prepared on AF Form 112, will be forwarded to the
Director of Intelligence, Headquarters United States Air Force.
(3) Commanding General, Air Materiel Command is authorized direct contact wlth major
Air Commands (overseas) and or ganizations under their contr ol in connection wlth the
development of information on this subject.
c. Major Air Commands (ZI)
(1) Reports wm be forwarded direct to the Commanding General, Air Materiel Command,
Wright-Patterson Air Force Base, Dayton, Ohio, Attn:
MCIAXO-3 by installations receiv­
ing information pertaining to the requirements enunciated in Part Il.
(2) Copies of such reports may be supplied the Command Headquarters of the installation
concerned.
(3) A copy of all reports sent to Air Materiel Command In accor dance with these instruc­
tions will be forwarded at the same time to the Director of Intelligence, Headquarters
United States Air Force.
(4) Written reports will be submitted on AF Form 112.
(5) Commanding Gener al, Air Materiel Command is authorized direct contact with major
Air Commands (ZI) and organizations under their control in connection with the develop­
ment of information on thls subject.
d. Non-Air Force Agencies
(1) Addressees ot~er than those of the United States Air Force are requested to forward
r eports direct to the Commanding General, Air Materiel Command, Wright-Patterson Air
Force Base, Dayton, Ohio, Attn: MCIAXO-3.
(2)
In order to reduce the time factor involved in transmission of this type of information
it is requested that, wherever communications facUlties permit, subordinate elements be
authorized to communicate reports direct to the Commanding General, Air Materiel Com­
mand.
PART ll - REQUffiEMENTS
General
1. Date of sighting.
2,
Time of sighting (zonal by 24 hr. clock).
3. Where sighted (observer's position):
a. Ground
(1) City, town.
(2) Distance and direction from city or town, road, intersection, etc.
(3) From bullding (story), yard, etc.
(4)
Map coordinates (if feasible) showing latitude and longitude.
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b. Al.r
(1) Type aircraft, speed, altitude, direction of flight.
(2) Distance and direction from city, town or known landmark.
(3)
Clock position of object from observer's aircraft.
(4) Latitude and longitude.
c. Sea
(1) Latitude and longitude.
(2) Proximity to land.
(Name clty, country, etc.)
4. Number of objects.
Formation type (if any), sketch If possible.
5. Observable celestial phenomena or planets that may account for the sighting. (Local facilities
or organizations which follow such celestial phenomena should be consulted for such information.)
6. Distance of object from observer.
'
a. Laterally or horizontally.
b. Angle of elevation from horizon.
C. Altitude.
7. Time in sight.
8. Appearance of object.
a. Color.
b. Shape.
(Sketch if possible)
c . Apparent construction.
(Of what material or substance)
d. Size.
(1) Estimated size.
(2) Size as l.t appeared from observer's view. (Compared to known object)
9. Direction of flight.
10. Tactics or maneuvers.
Vertical ascent or descent, horizontal, oscillating, fluttering, evasive, aggressive, erratic, etc.
11. Evidence of exhaust.
a. Color of smoke.
, b. Length and width.
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- 3 ­

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c. Odor (if any).
d. Rate of evaporation.
e. Does trail vary with sound?
(spurts)
12. Effect on clouds.
a. Opened path thru clouds.
b. Forced cloud or mists.
c. Reflected on cloud.
d. Showed thru cloud.
13. Lights.
a. Reflected or attached.
b. Luminous
c. Blinked on and off in r elation to speed.
14. Support
a. Wings .
b. Aerodynamic list of fuselage.
c. Vertical jet.
d. Rotating cylinder or cone.
e. Aerostatic 11ft (balloon or dirigible).
15. Propulsion.
a. Propeller or jet.
b. Rotor.
c. Aerodynamic vanes (flapping or oscillating) (Katz Mayer effect).
d. Visible exhaust or jet openings.
16. Control and stablll.ty.
a. Fins
b. Stabillzers (horizontal or vertical).
(1) Size.
(2) Shape.
(3) Locatlon.
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17. Air ducts.
a. Slots.
b. Duct openings.
18. Speed - M.P .H.
19. Sound.
a. Continuous whine or buzz.
b. Roar, whistle, w}:loosh.
C.
Intermittent.
20. Manner of disappearance.
a.
Explode.
(1) Possibility of fragments.
(2) Other physical evidence.
b. Faded from view.
C.
Disappeared behlnd obstacle.
Relative to the Observer
1.
Name of observer.
2. Address.
3. Occupation.
4. Place of business.
a. Employer or employee.
5. Pertinent hobbles.
a. Is observer amateur astronomer, pilot, engineer, etc.
b. Length of time engaged in bobby (experience).
6,
Ablllty to determine:
a. Color.
b. Speed of moving objects.
c. Size at distance.
7. Reliability of observer.
a. Sources.
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- 5 -

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(1) Neighbors.
(2) Police Dept.
(3) FBI records.
(4) Employer.
8. Notes relative to observer on:
a, Sightings in general.
b. How attention was drawn to object(s).
(1) Sound.
(2) Motion.
(3) Glint of Ught.
c. Degree of fatigue and duration of flight at time of sighting in cases where observer is
airborne.
9. Witnesses.
a. Addressees.
b. Occupation.
C. ReliabiUty.
10. Comments of interrogator regarding the intelUgence and character of person interrogated.
Relative to Radar Sightings
1. Re radars operating on ground.
a. Observations of range, speed, altitude and size of target.
b. D1d target executive any turns? If so, what angle (180°), etc. and what radius of turn.
If radius of turn 1s not observable, how long did the target stay in the turn and what was its speed?
c. Note particularly any separation of distant target into several targets upon approach. Track
all if possible.
2.
I.f airborne when object sighted.
a. Were there any radar inductions or extra noise on radio circuits?
b. Give estimates of size, speed, maneuvers, etc.
GENERAL
1. Teletype sequences of local weather conditions.
2.
Winds aloft report.
- 6 -
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3. Local flight schedules of commercial, private and military aircraft flying 1n viclnlty at the
time.
(Check Canadian actlvlty 1f close to that border.)
4. Possible releases of testing devices in vicinlty sent aloft by Ordnance, Navy, Air Force,
Army, Weather Units, Research Organizations or any other.
5. If object contacted earth, obtain soil samples within and without depression or spot where
object landed (and then presumably departed) for purpose of making comparison of solls.
6.
If object came sufflclently near other aircraft or known objects check surfaces with Gelger
counters for possible radioactivity. Make comparisons wlth other unaffected aircraft objects, etc.
7. Obtain photographs (or original negatives) where available; Ii not, secure sketches of:
a. Object.
b. Surrounding terrain where observed.
c. Place where it contacted earth (lf this happened).
d. Maneuvers.
e. Formation lf objects were more than two.
8. Secure signed statement.
9. Obtain fragments or physical evidence where possible.
10. Was any radio antenna to be observed, Le., (any projections or extentlons that might presum­
ably be construed as such).
c>: P.~
C. P . CABELL
Major General, USAF
Director of Intelllgence, Office of
Deputy Chief of Staff, Operations
DISTRIBUTION:
Commanding Generals, Major Air Commands,
ZI and Overseas
All United States Air Attaches
Director of Central Intelligence
Special Assistant for Research and Intelligence,
Department of State
Director of Intelligence, GSUSA
Chief of Naval Intelligence
Commandant (INT), United States Coast Guard
Director, Federal Bureau of Investigation
RESTRICTED
- 7 -

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RESTRICTED

RESTRICTED
DEPARTMENT OF THE Affi F ORCE
HEADQUARTERS UNITED STATES AIR FORCE
DffiECTORATE OF INTELLIGENCE
WASHINGTON 25, D. C.
15 February 1949
Affi INTELLIGENCE REQUIB.EMENTS
MEMORANDUM NUMBER 4
UNCONVENTIONAL AffiCRAFT
PART I - GENERAL
1. PURPOSE
The purpose of this memorandum is twofold:
a. To enunciate contlnulng Air Force r equirements for information pertaining to sightings of
unconventional aircraft and unidentified flying objects, including the so-called "Flying Dlscs."
b. To establish procedures for reporting such information.
2. RESCISSION
Department of the Army Collection Memorandum Number 7, dated 21 January 1948, and letter,
CSGID 425.1, dated 25 March 1948, both subject as above, which have been transferred to Air
Force agencies for action, ar e herewith super seded.
3. REPORTING
a.
General
(1) As complete an answer to the requirements enunciated in Part II, as may be procur­
able, should be dispatched by means of electrical transmission immediately after sightings.
(2) Supplementary reports should be forwarded as available by the
consistent with the importance of the lnformation r eported.
most expeditious means
b. Major Air Commands (Over seas) and Air Attaches
(1) Initial and supplementary cabled reports will be transmitted to the Director of Intem­
gence, Headquarters United Stat<::s Air Force. Cables will contain the phase, " Pass to
COMGENAMC WRIGHT-PATTERSON AFB, DAYTON, OHIO, ATTN:
MCIAXO-3."
RESTRICTED
C9-IIH2,AF

RESTRICTED
(2) Supplementary written reports, prepared on AF Form 112, will be forwarded to the
Director of Intelligence, Headquarters United States Air Force.
(3) Commanding General, Air Materiel Command is authorized direct contact with major
Air Commands (overseas) and organizations under their control in connection with the
development of information on this subject.
c. Major Air Commands (ZI)
(1) Reports w111 be forwarded direct to the Commanding General, Air Materiel Command,
Wright-Patterson Air Force Base, Dayton, Ohio, Attn: MCIAX0-3 by installations receiv­
ing Information pertaining to the requirements enunciated in Part II.
(2) Coples of such reports may be supplled the Command Headquarters of the Installation
concerned.
(S) A copy of all reports sent to Air Materiel Command in accordance with these Instruc­
tions wlll be forwarded at the same time to the Director of Intelligence, Headquarters
United States Air Force.
(4) Written r eports will be submitted on AF Form 112.
(5) Commanding General, Air Materiel Command ls authorized direct contact with major
Air Commands (ZI) and or ganizations under their control in connection with the develop­
ment of information on this subject.
d.
Non-Air Force Agencies
(1) Addressees o~er than those of the United States Air Force are requested to forward
reports direct to the Commanding General, Air Materiel Command, Wright-Patterson Air
Force Base, Dayton, Ohio, Attn: MCIAX0-3.
(2) In order to reduce the time factor involved in transmission of this type of information
1t is requested that, wherever communications fac1litles permit, subordinate elements be
authorized to communicate reports direct to the Commanding General, Air Materiel Com­
mand.
PART Il - REQUIREMENTS
General
1. Date of sighting.
2. Time of sighting (zonal by 24 hr. clock).
3. Where sighted (observer's position):
a. Ground
(1) City, town.
(2) Distance and direction from city or town, road, intersection, etc.
(3)
From building (story), yard, etc.
(4) Map coordinates (If feasible) showing latitude and longitude.
- 2 -
RESTRICTED

RESTRICfED
b. Air
(1) Type aircraft, speed, altitude, direction of flight.
(2)
Distance and direction from city, town or known landmark.
(3) Clock position of object from observer's aircraft.
(4)
Latitude and longitude.
c. Sea
(1)
Latitude and longitude.
(2) Proxlml.ty to land.
(Name city, country, etc.)
4.
Number of objects.
Formation type (!.f any), sketch l.f possible.
5. Observable celestial phenomena or planets that may account for the sighting.
(Local fac111ties
or organizations which follow such celestial phenomena should be consulted for such information.)
6. Distance of object from observer.
a. Laterally or horizontally.
b. Angle of elevation from horizon.
c. Altitude.
7. Time 1n sight.
8. Appearance of object.
a. Color.
b. Shape.
(Sketch l.f possible)
c. Apparent construction.
(Of what material or substance)
d. Sii.e.
(1)
Estimated size.
(2)
Sl.ze as lt appeared from observer's view.
(Compared to known object)
9. Direction of flight.
10. Tactics or maneuvers.
Vertical ascent or descent, horizontal, oscillating, fluttering, evasive, aggressive, erratic, etc.
11. Evidence of exhaust.
a. Color of smoke.
1 b. Length and width.
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- 3 ­

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c. Odor (if any).
d. Rate of evaporation.
e.
Does trail vary with sound?
(spurts)
12.
Effect on clouds.
a. Opened path thru clouds.
b.
Forced cloud or mists.
c. Reflected on cloud.
d.
Showed thru cloud.
13. Lights.
a.
Reflected or attached.
b.
Luminous
c.
Blinked on and off in relation to speed.
14. Support
a. Wings.
b.
Aerodynamic 11st of fuselage.
c. Vertical jet.
d.
Rotating cylinder or cone.
e.
Aerostatic lift (balloon or dirigible).
15. Pr opulsion.
a.
P ropeller or jet.
b.
Rotor.
c.
Aerodynamic vanes (flapping or oscillating) (Katz Mayer effect).
d. Visible exhaust or jet openings.
16. Control artd stability.
a.
F!.ns
b.
Stabilizers (hor izontal or vertical).
(1) Size.
(2) Shape.
(3) Location.
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17. Air ducts.
a.
Slots.
b. Duct openings.
18. Speed - M.P.H.
19. Sound.
a. Continuous whine or buzz.
b. Roar, whistle, whoosh.
c. Intermittent.
20. Manner of disappearance.
a.
Explode.
(1) Possibility of fragments.
(2) Other physical evidence.
b. Faded from view.
c.
Disappeared behind obstacle.
Relative to the Observer
1. Name of observer.
2. Address.
3.
Occupation.
4. Place of business.
a.
Employer or employee.
5. Pertinent hobbies.
a. Is observer amateur astronomer, pilot, engineer, etc.
b. Length of time engaged in hobby (experience).
6. AbHity to determine:
a. Color.
b. Speed of moving objects.
c. Size at distance.
7. Reliab111ty of observer.
a.
Sources.
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- 5 -

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(1) Neighbors.
(2) Police Dept.
(3) FBI records.
(4) Employer.
8. Notes relative to observer on:
a . Sightings in general.
b.
How attention was drawn to object(s).
(1) Sound.
(2) Motion.
(3) Glint of light.
c. Degree of fatigue and duration of flight at time of slghtlng in cases where observer ls
airborne.
9. Witnesses.
a. Addressees.
b. Occupation.
c. Rellablllty.
10. Comments of interrogator regarding the intelllgence and character of person interrogated.
Relative to Radar Sightings
1. Re radars operating on ground.
a. Observations of range, speed, altitude and size of target.
b.
Did target executive any tw-ns? If so, what angle (180°), etc. and what radius of turn.
If radius of turn ls not observable, how long did the target stay in the turn and what was its speed?
c.
Note particularly any separation of distant target into several targets upon approach. Track
all if possible.
2. If airborne when object sighted.
a. Were there any radar inductions or extra noise on radio circuits?
b. Give estimates of size, speed, maneuvers, etc.
GENERAL
1. Teletype sequences of local weather conditions.
2. Winds aloft report.
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3. Local filght schedules of commercial, private and mmtary aircraft flylng In vicinity at the
time.
(Check Canadian activity If close to that border.)
4. Possible releases of testing devices In vicinity sent aloft by Ordnance, Navy, Air Force,
Army, Weather Units, Research Organizations or any other.
5. If object contacted earth, obtain soil samples within and without depression or spot where
object landed (and then presumably departed) for purpose of making comparison of soils.
6.
11 object ca.me sufficiently near other aircraft or known objects check surfaces with Gelger
cowiters for possible radioactivity. Make comparisons with other unaffected aircraft objects, etc.
7. Obtain photographs (or original negatives) where available; 1f not, secure sketches of:
a. Object.
b. Surrounding terrain where observed.
c. Place where lt contacted earth (lf this happened).
d. Maneuvers.
e. Formation Ii objects were more than two.
8. Secure signed statement.
9. Obtain fragments or physical evidence where possible .
10. Was any radio antenna to be observed, Le., (any projections or extentlons that might presum­
ably be construed as such).
C. P. CABELL
Major General, USAF
Director of Intelllgence, Office of
Deputy Chief of Staff, Operations
DISTRIBUTION:
Commanding Gener als, Major Air Commands,
ZI and Overseas
All United States Air Attaches
Dir ector of Central Intelligence
Special Assistant for Research and IntelUgence,
Department of State
Director of Intell1gence, GSUSA
Chief of Naval Intelllgence
Commandant (INT), United States Coast Guard
DI.rector, Federal Bureau of Investigation
RESTRIC TED
- 7 -

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RESTRICTED

RESTRICTED
DEPARTMENT OF THE AIR FORCE
HEADQUARTERS UNITED STATES AIR FORCE
DIRECTORATE OF INI'ELLIGENCE
WASHINGTON 25, D. C.
15 February 1949
AIR INTELLIGENCE REQUIREMENTS
MEMORANDUM NUMBER 4
UNCONVENTIONAL AIRCRAFT
PART I - GENERAL
1. PURPOSE
The purpose of this memorandum Is twofold:
a. To enunciate continuing Air Force requirements for information pertaining to sightings of
unconventional aircraft and unidentlfied flying objects, including the so-called "Flying Discs."
b. To establish procedures for reporting such information.
2. RESCISSION
Department of the Army Collection Memorandum Nwnber 7, dated 21 January 1948, and letter,
CSGID 425.1, dated 25 March HM8, both subject as above, which have been transferred to Air
Force agencies for action, are herewith superseded.
3. REPORTING
a. General
(1) As complete an answer to the requirements enunciated in Part II, as may be procur­
able, should be dispatched by means of electrical transmission immediately after sightings.
(2) Supplementary reports should be forwarded as available by the most expeditious means
consistent with the importance of the information reported.
b. Major Air Commands (Overseas) and Air Attaches
(1)
Initial and supplementary cabled reports will be transmitted to the Director of Intelll­
gence, Headquarters United States Air Force. Cables wm contain the phase, " Pass to
COMGENAMC WRIGHT-PATTERSON AFB, DAYTON, OHIO, ATTN: MCIAX0-3."
RESTRICTED
Cll-11892, AF

RESTRICTED
(2) Supplementary wr1tten reports, prepared on AF Form 112, will be forwarded to the
Director of Intelligence, Headquarters United States Air Force.
(3)
Commanding General, Air Materiel Command is authorized direct contact with major
Air Commands (overseas) and organizations under their control in connection with the
development of information on this s ubject.
c. Major Air Commands (ZI)
(1) Reports wlll be forwarded direct to the Commanding General, Air Materiel Command,
Wright-Patterson Air Force Base, Dayton, Ohio, Attn:
MCIAXO-3 by installations r eceiv­
ing information pertaining to the requirements enunciated in Part II.
(2) Copies of such reports may be supplied the Command Headquarters of the installation
concerned.
(3) A copy of all reports sent to Air Materiel Command in accordance with these instruc­
tions wlll be forwarded at the same time to the Director of Intelligence, Headquarters
United States Air Force.
(4) Written reports will be submitted on AF Form 112.
(5) Commanding General, Air Materiel Command 1s authorized direct contact with major
Air Commands (ZI) and organizations under their control in connection with the develop­
ment of information on this subject.
d. Non-Air Force Agencies
(1) Addressees ot~er than those of the United States Air Force are r equested to forward
reports direct to the Commanding General, Air Materiel Command, Wright-Patterson Air
Force Base, Dayton, Ohio, Attn: MCIAXO-3.
(2) In order to reduce the time factor involved in transmission of this type of information
it is requested that, wher ever communications fac111ties permit, subordinate elements be
authorized to communicate reports direct to the Commanding General, Air Materiel Com­
mand.
PART II - REQUIREMENTS
General
1. Date of sighting.
2. Time of sighting (zonal by 24 hr. clock).
3. Where sighted (observer's position):
a.
Ground
(1) City, town.
(2) Distance and direction from city or town, r oad, intersection, etc.
(3) From building (story), yard, etc.
(4) Map coordinates (if feasible) showing latitude and longitude.
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b.
Air
(1) Type aircraft, speed, altltude, direction of flight.
(2) Distance and direction from city, town or known landmark.
(3) Clock position of object from observer's aircraft.
(4) Latitude and longitude.
c. Sea
(1) Latitude and longitude.
(2) Proximity to land.
(Name city, country, etc.)
4.
Number of objects.
Formation type (if any), sketch if possible.
6. Observable celestial phenomena or planets that may account for the sighting.
(Local facillties
or organizations which follow such celestial phenomena should be consulted for such information.)
6. Distance of object from observer.
a. Laterally or horizontally.
b. Angle of elevation from horizon.
C. Altitude.
7. Time in sight.
8. Appearance of object.
a. Color.
b. Shape. (Sketch if possible)
c. Apparent construction.
(Of what material or substance)
d. Size.
(1) Estimated size.
(2) Size as it appeared from observer's view. (Compared to known object)
9. Direction of flight.
10. Tactics or maneuvers.
Vertical ascent or descent, horizontal, oscillating, fluttering, evasive, aggressive, erratic, etc.
11. Evidence of exhaust.
a. Color of smoke.
, b. Length and width.
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- 3 ­
•

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C. Odor (if any).
d. Rate of evaporation.
e. Does trail va:ry with sound?
(spurts)
12. Effect on clouds.
a. Opened path thru clouds.
b.
Forced cloud or mists.
c. Reflected on cloud.
d. Showed thru cloud.
13. Lights.
a.
Reflected or attached.
b. Luminous
c. Blinked on and off ln relation to speed.
14. Support
a. Wings.
b. Aerodynamic list of fuselage.
c. Vertical jet,
d. Rotating cylinder or cone.
e. Aerostatic lift (balloon or dirigible).
15. Propulsion.
a. Propeller or jet.
b. Rotor.
c. Aerodynamic vanes (flapping or oscillating) (Katz Mayer effect).
d. Visible exhaust or Jet openings.
16. Control and stability.
a . Fins
b. Stabillzers (horizontal or vertical).
(1) Size.
(2) Shape.
(3) Location.
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17. Air ducts.
a. Slots.
b. Duct openings.
18. Speed - M.P.H.
19. Sound.
a. Continuous whine or buzz.
b. Roar, whistle, wl;loosh.
c. Intermittent.
20. Manner of disappearance.
a. Explode.
(1)
Possibility of fragments.
(2)
Other physical evidence.
b. Faded from view.
c. Disappeared behind obstacle.
Relative to the Observer
1. Name of observer.
2. Address.
3, Occupatlon.
4. Place of business.
a. Employer or employee.
5. Pertinent hobbies.
a. Is observer amateur astronomer, pl.lot, engineer , etc.
b. Length of time engaged in hobby (experience).
6. Ability to determine:
a. Color.
b. Speed of moving objects.
c. Size at distance.
7. Reliabi11ty of observer.
a. Sources.
RESTRIC TED
- 5 -

RESTRICTED
(1) Neighbors.
(2) Police Dept.
(3) FBI records.
(4) Employer.
8. Notes relative to observer on:
a. Sightings in general.
b. How attention was drawn to object(s).
(1) Sound.
(2) Motion.
(3) Glint of light.
c. Degree of fatigue and duration of flight at time of sighting in cases where observer ls
airborne.
9. Witnesses.
a. Addressees.
b. Occupation.
C.
Reliablllty.
10. Comments of interrogator regarding the lntelllgence and character of person interrogated.
Relative to Radar Sightings
1. Re radars operating on ground.
a. Observations of range, speed, altitude and size of target.
b. Did target executive any turns? If so, what angle (180°), etc. and what radius of turn.
If radius of turn is not observable, how long did the target stay in the turn and what was its speed?
c. Note particularly any separation of distant target into several targets upon approach. Tr ack
all if possible.
2. I! airborne when object sighted.
a. Were there any radar inductions or extra noise on radlo circuits?
b. Give estimates of size, speed, maneuvers, etc.
GENERAL
1. Teletype sequences of local weather conditions.
2. Winds aloft report.
- 6 -
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3. Local fl1ght schedules of commercial, private and military aircraft flying ln vicfnity at the
time.
(Check Canadian activity 1f close to that border.)
4. Possible releases of testing devices 1n vicinity sent aloft by Ordnance, Navy, Air Force,
Army, Weather Units, Research Organizations or any other.
5. Ii object contacted earth, obtain soil samples within and without depr ession or spot where
object landed (and then presumably departed) for purpose of making comparison of soils.
6. If object came sufficiently near other aircraft or known objects check surfaces with Geiger
counters for possible radioactivity. Make comparisons with other unaffected aircraft objects, etc.
? . Obtain photographs (or original negatives) where available; 1f not, secure sketches of:
a. Object.
b. Surrounding terrain where observed.
c. Place where it contacted earth (if this happened).
d.
Maneuvers.
e. Formation 1f objects were more than two.
8. Secure signed statement.
9. Obtain fragments or physical evidence where possible.
10. Was any r adio antenna to be observed, i.e ., (any projections or extentions that might presum­
ably be construed as such).
C. P . CABELL
Major General, USAF
Director of Intel11gence, Office of
Deputy Chief of Staff, Operations
DISTRlBUTION:
Commanding Generals, Major Air Commands,
ZI and Overseas
All United States Air Attaches
Director of Central Intelligence
Special Assistant for Research and Intelllgence,
Department of State
Director of Intelligence, GSUSA
Chief of Naval Intelligence
Commandant (INT), United States Coast Guard
Director, Federal Bureau of Investigation
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- ? -

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RESTRICTED

RESTRICTED
DEPARTMENT OF THE AIR FORCE
HEADQUARTERS UNITED STATES AIR FORCE
DmECTORATE OF INTELLIGENCE
WASHINGTON 25, D. C.
15 February 1949
AIR INTELLIGENCE REQUIREMENTS
MEMORANDUM NUMBER 4
UNCONVENTIONAL AIRCRAFT
PART I - GENERAL
1. PURPOSE
The purpose of this memorandum is twofold:
a.
To enunciate continuing Air Force requirements for informatlon pertaining to sightings of
unconventional aircraft and unldentifi.ed flying objects, including the so-called "Flying Discs.,,
b.
To establish procedures for reporting such information.
2.
RESCISSION
Department of the Army Collection Memorandum Number 7, dated 21 January 1948, and letter,
CSGID 425.1, dated 25 March 1948, both subject as above, which have been transferred to Air
Force agencies for action, are herewith super seded.
3. REPORTING
a.
General
(1) As compl ete an answer to the requirements enunciated in Part Il, as may be procur­
able, should be dispatched by means of electrical transmission immediately after sightings,
(2) Supplementary r eports should be forwarded as available by the most expeditlous means
consistent with the importance of the information r eported.
b. Major Air Commands (Over seas) and Air Attaches
(1) Initial and supplementary cabled r eports will be transmitted to the Director of Intelli­
gence, Headquarters United States Air Force. Cables wlll contain the phase, " Pass to
COMGENAMC WRIGHT-PATTERSON AFB, DAYTON, OHIO, ATTN: MCIAX0-3.''
RESTRICTED
ce-,as2,AF
ha ff 1K 9~-/t''/
r

RESTRICTED
(2) Supplementary written r eports, prepared on AF Form 112, wm be forwarded to the
Director of IntelHgence, Headquarters United States Air Force.
(3) Commanding General, Alr Materiel Command ls authorized direct contact with major
Air Commands (overseas) and organizations under their control in connection with the
development of information on this subject.
c. Major Air Commands (ZI)
(1) Reports will be forwarded direct to the Commanding General, Air Materiel Command,
Wright-Patterson Alr Force Base, Dayton, Ohio, Attn:
MCIAXO-3 by installations receiv­
ing information pertaining to the requirements enunciated in Part II.
(2) Copies of such r eports may be supplied the Command Headquarters of the installation
concerned.
(3) A copy of all reports sent to Air Materiel Command in accordance with these instruc­
tions will be forwarded at the same time to the Director of Intelligence, Headquarters
United States Air Force.
(4) Written reports will be submitted on AF Form 112.
(5) Commanding General, Air Materiel Command is authorized direct contact with major
Air Commands (ZI) and organizations under their control in connection with the develop­
ment of information on this subject.
d.
Non-Air Force Agencies
(1) Addressees otter than those of the United States Air Force are r equested to forward
reports direct to the Commanding General, Air Materiel Command, Wright-Patterson Air
Force Base, Dayton, Ohio, Attn: MCIAXO-3.
(2) In order to reduce the time factor involved in transmission of this type of information
it is requested that, wherever communications facilltles permit, subordinate elements be
authorized to communicate reports direct to the Commanding General, Alr Materiel Com­
mand.
PART II - REQUIREMENTS
General
1. Date of sighting.
2. Time of slghtl.ng (zonal by 24 hr. clock).
3. Where sighted (observer's position):
a. Ground
(1) City, town.
(2) Distance and direction from city or town, road, intersection, etc.
(3)
From building (story), yard, etc.
(4) Map coordinates (if feasible) showing latitude and longitude.
- 2 -
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b. Air
(1)
Type aircraft, speed, altitude, direction of fUght.
(2) Distance and direction from city, town or known landmark.
(3)
Clock position of object from observer's aircraft.
(4) Latitude and longitude.
c. Sea
(1) Latitude and longitude.
(2) Proximity to land.
(Name city, country, etc.)
4.
Number of objects.
Formation type (If any), sketch if possible.
5. Observable celestial phenomena or planets that may account for the sighting.
(Local facilltles
or organizations which follow such celestial phenomena should be consulted for such information.)
6. Distance of object from observer.
a. Laterally or horizontally.
b.
Angle of elevation from horizon.
c. Altitude.
7.
Time in sight.
8.
Appearance of object.
a. Color.
b. Shape.
(Sketch if possible)
c. Apparent constructlon.
(Of what material or substance)
d. Size.
(1)
Estimated size.
(2) Size as it appeared from observer's view.
(Compared to known object)
9. Direction of flight.
10. Tactics or maneuvers.
Vertical ascent or descent, horizontal, oscillating, fluttering, evasive, aggressive, erratlc, etc.
11. Evidence of exhaust.
a. Color of smoke.
, b.
Length and width.
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c. Odor (if any).
d. Rate of evaporatlon.
e.
Does trail vary with sound?
(spurts)
12. Effect on clouds.
a.
Opened path thru clouds.
b.
Forced cloud or mists.
c.
Reflected on cloud.
d. Showed thru cloud.
13. Lights.
a.
Reflected or attached.
b.
Luminous
c. Blinked on and off in relation to speed.
14. Support
a. Wings .
b.
Aerodynamic list of fuselage.
c. Vertical jet.
d.
Rotating cylinder or cone.
e.
Aerostatic lift (balloon or dirigible).
15. Propulsion.
a.
Propeller or jet .
b. Rotor .
c. Aerodynamic vanes (-flapping or oscl.llating} (Katz Mayer effect).
d. Visible exhaust or jet openings.
16. Control and stability.
a. Fins
b. Stabilizers (hor izontal or vertical).
(1) Size.
(2) Shape.
(3)
Location.
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RESTRICTED
17. Air ducts.
a. Slots.
b. Duct openings.
18. Speed - M.P .H.
19. Sound.
a. Continuous whine or buzz.
b. Roar, whistle, whoosh.
C.
Intermittent.
20. Manner of disappearance.
a.
Explode.
(1)
Possibility of fragments.
(2)
Other physical evidence.
b. Faded from view.
c. Disappeared behind obstacle.
Relative to the Observer
1. Name of observer.
2. Address.
3, Occupation.
4. Place of business.
a. Employer or employee.
5.
Pertinent hobbies.
a. Is observer amateur astronomer, pilot, engineer, etc.
b. Length of time engaged in hobby (experience).
6. Ab111ty to determine:
a. Color.
b. Speed of moving objects.
c. Size at distance.
7. Reliabillty of observer.
a. Sources.
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- 5 -

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(1)
Neighbors.
(2)
Pollce Dept.
(3) FBI records.
(4) Employer.
8. Notes relative to observer on;
a. Sightings In general.
b. How attention was drawn to object(s).
(1) Sound,
(2) Motion.
(3) Glint of Ught.
c. Degree of fatigue and duration of flight at time of sighting in cases where observer ls
airborne.
9. Witnesses.
a. Addressees.
b.
Occupation.
c. Reliablllty.
10. Comments of Interrogator regarding the l.ntell1gence and character of person Interrogated.
Relative to Radar Sightings
1. Re radars operating on ground.
a. Observations of range, speed, altitude and size of target.
b.
Did target executive any turns? If so, what angle (180°), etc. and what radius of turn.
If radius of turn is not observable, how long did the target stay in the turn and what was I.ts speed?
c, Note particularly any separation of distant target into several targets upon approach. Tr ack
all l.f possible.
2.
If airborne when object sighted.
a. Were there any radar inductions or extra noise on radio circuits?
b. Give estimates of slze, speed, maneuvers, etc.
GENERAL
1. Teletype sequences of local weather condtuons.
2. Winds aloft report.
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3. Local flight schedules of commercial, private and military aircra!t flying 1n vicinity at the
time.
(Check Canadian activity 1f close to that border.)
4. Possible releases of testing devices 1n vicinity sent aloft by Ordnance, Navy, Air Force,
Army, Weather Units, Research Organizations or any other.
5. If object contacted earth, obtain soil samples within and without depression or spot where
object landed (and then presumably departed) for purpose of making comparison of soils.
6.
11 object came sufficiently near other alrcra!t or known objects check surfaces with Geiger
counters for possible radioactivity. Make comparisons with other unaffected a1rcra!t objects, etc.
7. Obtain photographs (or original negatives) where available; if not, secure sketches of:
a. Object.
b. Surrounding terrain where observed.
c. Place where it contacted earth (If this happened).
d. Maneuvers.
e. Formation 1f objects were more than two.
8. Secure signed statement.
9. Obtain fragments or physical evidence wher e possible.
10. Was any radio antenna to be observed, Le., (any projections or extentl.ons that might presum­
ably be construed as such).
C. P. CABELL
Major General, USAF
Director of Intelligence, Office of
Deputy Chief of Sta!f, Operations
DISTRIBUTION:
Commanding Generals, Major Air Commands,
ZI and Overseas
All United States Air Attaches
Director of Central Intelligence
Special Assistant for Research and Intelligence,
Department of State
Director of Intelllgence, GSUSA
Chief of Naval Intelligence
Commandant {INT), United States Coast Guard
Director, Federal Bureau of Investigation
RESTRICTED
- 7 -

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RESTRICTED

RESTRICTED
DEPARTMENT OF THE AIR FORCE
HEADQUARTERS UNITED STATES AIR FORCE
DIRECTORATE OF INTELLIGENCE
WASHINGTON 25, D. C.
15 February 1949
AIR INTELLIGENCE REQUIREMENTS
MEMORANDUM NUMBER 4
UNCONVENTIONAL AIRCRAFT
PART I - GENERAL
1.
PURPOSE
The purpose of this memorandum is twofold:
a. To enunciate continuing Air Force requirements for information pertaining to sightings of
unconventional aircraft and unidentified flying objects, including the so-called "Flying Discs.''
b. To establish procedures for reporting such information.
2. RESCISSION
Department of the Army Collection Memorandum Number 7, dated 21 January 1948, and letter,
CSGID 425.1, dated 25 March 1948, both subject as above, which have been transferred to Air
Force agencles for action, are herewith superseded.
3. REPORTING
a.
General
(1) As complete an answer to the requirements enunciated in Part n, as may be procur­
able, should be dispatched by means of electrical transmission immediately after sightings.
(2) Supplementary reports should be for warded as available by the most expeditious means
consistent with the importance of the information reported.
b. Major Air Commands (overseas) and Air Attaches
(1) Initial and supplementary cabled reports wm be transmitted to the Director of IntelU­
gence, Headquarter s United State:s Air Force. Cables wlll contain the phase, "Pass to
COMGENAMC WRIGHT-PATTERSON AFB, DAYTON, OHIO, ATTN: MCIAX0-3."
RESTRICTED
ce- 11892, AF

RES TRICTED
(2) Supplementary written reports, prepared on AF Form 112, will be forwarded to the
Director of Intelllgence, Headquarters United States Air Force.
(3) Commanding General, Air Materiel Command ls authorized direct contact with major
Air Commands (overseas) and organizations Wlder their control in connection with the
development of information on this subject.
c. Major Air Commands (ZI)
(1) Reports will be forwarded direct to the Commanding General, Air Materiel Command,
Wright-Patterson Air Force Base, Dayton, Ohio, Attn:
MCIAX0-3 by installations r eceiv­
ing information pertaining to the requirements enW1ciated in Part II.
(2) Copies of such reports may be supplled the Command Headquarters of the installation
concerned.
(3)
A copy of all reports sent to Air Materiel Command in accordance with these instruc­
tions wlll be forwarded at the same time to the Director of Intelligence, Headquarters
United States Air Force.
(4) Written reports will be submitted on AF Form 112.
(5) Commanding General, Air Materiel Command ls authorized direct contact with major
Air Commands (ZI) and organizations W1der their control in connection with the develop­
ment of information on this subject.
d. Non-Air Force Agencies
(1) Addressees o~er than those of the United States Air Force are r equested to forward
reports direct to the Commanding General, Air Materiel Command, Wright-Patterson Air
Force Base, Dayton, Ohio, Attn: MCIAX0-3.
(2) In order to reduce the time factor lnvolved ln transmission of this type of lnformatlon
it ls r equested that, wherever communications faciUtles permit, subordinate elements be
authorized to communicate reports direct to the Commanding General, Air Materiel Com­
mand.
PART II - REQUffiEMENTS
General
1. Date of sighting.
2. Time of sighting (zonal by 24 hr. clock).
3. Wher e sighted (observer 's position):
a. Ground
(1) City, town.
(2) Distance and direction from city or town, road, intersection, etc.
(3) Fr om building (story), yard, etc.
(4) Map coordinates (I! feasible) showing latitude and longitude.
- 2 -
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b. Air
(1) Type aircraft, speed, altitude, direction of flight.
(2) Distance and direction from city, town or known landmark.
(3)
Clock position of object from observer 's aircraft.
(4) Latitude and longitude.
c. Sea
(1) Latitude and longitude.
(2)
Proximity to land.
(Name city, country, etc.)
4.
Number of objects.
Formation type (if any), sketch if possible.
5. Observable celestial phenomena or planets that may account for the sighting.
(Local facl.llties
or organizations which follow such celestial phenomena should be consulted for such information.)
6. Distance of object from observer.
a. Laterally or horizontally.
b. Angle of elevation from horizon.
c. Altitude.
7. Time in sight.
8. Appearance of object.
a. Color.
b. Shape.
(Sketch if possible)
c. Apparent construction.
(Of what material or substance)
d. Size.
(1) Estimated size.
(2) Size as it appeared from observer's view. (Compared to known object)
9. Direction of flight.
10. Tactics or maneuvers.
Vertical ascent or descent, horizontal, osclllatl.ng, fluttering, evasive, aggressive, erratic, etc.
11. Evidence of exhaust.
a. Color of smoke.
•b. Length and width.
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- 3 -
•

RESTRICTED
c. Odor (if any).
d. Rate of evaporation.
e. Does trail va:ry with sound? (spurts)
12.
Effect on clouds.
a.
Opened path thru clouds.
b. Forced cloud or mists .
c. Reflected on cloud.
d. Showed thru cloud.
13. Llghts.
a. Reflected or attached.
b. Luminous
i
c. Blinked on and off in relation to speed.
14, Support
a. Wings.
b. Aerodynamic 11st of fuselage.
c. Vertical jet.
d. Rotating cylinder or cone.
e. Aerostatic lift (balloon or dirigible).
15. Propulsion.
a.
Pr opeller or jet.
b.
Rotor.
c. Aerodynamic vanes (flapping or osclllating) (Katz Mayer effect).
d.
Visible exhaust or jet openings.
16. Control and stability.
a. Fins
b. StabiUzer s (horizontal or vertical).
(1) Size.
(2) Shape.
(3) Location.
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17. Air ducts.
a. Slots.
b.
Duct openings.
18. Speed - M.P.H.
HJ.
Sound.
a, Continuous whine or buzz.
b. Roar, whistle, wt)oosh.
c.
Intermittent.
20. Manner of disappearance.
a.
Explode.
(1) PossibHity of fragments.
(2) Other physical evidence.
b, Faded from view.
c. Disappeared behind obstacle.
Relative to the Observer
1. Name of observer.
2. Address.
3. Occupation.
4. Place of business.
a. Employer or employee.
5. Pertinent hobbies.
a. Is observer amateur astronomer, pilot, engineer, etc.
b. Length of time engaged in hobby (experience).
6.
Ab111ty to determine:
a. Color.
b. Speed of moving objects.
c. Size at distance.
7. Reliablll.ty of observer.
a. Sources.
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- 5 -

RESTRICTED
(1) Neighbors.
(2) PoUce Dept.
(3) FBI records.
(4) Employer.
8. Notes relative to observer on:
a.
Sightings 1n general.
b. How attention was drawn to object(s).
(1) Sound.
(2) Motion.
(3) Glint of light.
c. Degree of fatigue and duration of flight at time of sighting In cases where observer ls
airborne.
9. Witnesses.
a. Addressees.
b.
occupation.
c . Reliab111ty.
10. Comments of interrogator regarding the 1nte1Ugence and character of person interrogated.
Relative to Radar Sightings
1. Re radars operating on ground.
a. Observations of range, speed, altitude and size of target.
b.
Did target executive any turns? If so, what angle (180°), etc. and what radius of turn.
If radius of turn ls not observable, how long did the target stay 1n the turn and what was Its speed?
c. Note particularly any separation of distant target Into several targets upon approach. Track
all Ii possible.
2. If airborne when object sighted.
a. Were there any radar inductions or extra noise on radio circuits?
b. Give estimates of size, speed, maneuvers, etc.
GENERAL
1. Teletype sequences of local weather conditions.
2. Winds aloft report.
- 6 -
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S. Local flight schedules of commercial, private and military aircraft :flying in vic!nlty at the
time.
(Check Canadian activity 1f close to that border.)
4. Possible releases of testing devlces in vicinity sent aloft by Ordnance, Navy, Air Force,
Ar my, Weather Units, Research Organlzatlons or any other.
5. If object contacted earth, obtain soll samples within and without depression or spot where
object landed (and then presumably departed) for purpose of making comparison of soils.
6.
If object came sufficiently near other aircraft or lmown objects check surfaces with Gelger
counters for possible rad1oact1v1ty. Make comparisons with other unaffected aircraft objects, etc.
7. Obtain photographs (or original negatives) where available; if not, secure sketches of:
a. Object.
b. Surrounding terrain where observed.
c. Place where it contacted earth (lf this happened).
d. Maneuvers.
e. Formation lf objects were more than two.
8. Secure signed statement.
9. Obtain fragments or physical evidence where possible.
10. Was any radio antenna to be observed, Le., (any projections or extentlons that might presum­
ably be construed as such).
c:P.~
C. P. CABELL
Major General, USAF
Director of Intelllgence, Office of
Deputy Chief of Staff, Operations
DISTRIBUTION:
Commanding Generals, Major Alr Commands,
ZI and Overseas
All United States Alr Attaches
Director of Central Intelligence
Special Assistant for Resear ch and Intelligence,
Department of State
Director of Intelligence, GSUSA
Chief of Naval Intelllgence
Commandant (I.NT), United States Coast Guard
Director , Federal Bureau of Investigation
RESTRICTED
- 7 -

RESTRICTED
RESTRICTED

RESTRICTED
DEPARTMENT OF THE AIR FORCE
HEADQUARTERS UNITED STATES AIR FORCE
DIRECTORATE OF INTELLIGENCE
WASHINGTON 25, D. C.
15 February 1949
AIR INTELLIGENCE REQUIREMENTS
MEMORANDUM NUMBER 4
UNCONVENTIONAL AIRCRAFT
PART I - GENERAL
1. PURPOSE
The purpose of this memorandum ls twofold:
a. To enunciate continuing Air Force requirements for information pertaining to sightings of
unconventional aircraft and unldentlfled flying objects, including the so-called "Flying Discs."
b. To establish procedures for reporting such information.
2. RESCISSION
Department of the Army Collection Memorandum Number 7, dated 21 January 1948, and letter,
CSGID 425.1, dated 25 March 1948, both subject as above, which have been transferred to Air
Force agencies for action, are herewith superseded.
3. REPORTING
a. General
(1) As complete an answer to the requirements enunciated in Part II, as may be procur­
able, should be dispatched by means of electrical transmission immediately after sightings,
(2) Supplementary reports should be forwarded as ava1lable by the most expeditious means
consistent with the importance of the information reported.
b, Major Air Commands (Overseas) and Air Attaches
(1) Initial and supplementary cabled reports wlll be transmitted to the Director of Intem­
gence, Headquarters United States Al.r Force. Cables wl.11 contain the phase, " Pass to
COMGENAMC WRIGHT-PATTERSON AFB, DAYTON, OHIO, ATTN:
MCIAXO-3."
RESTRICTED
ta- 8~k94'-/~1/

RESTRICTED
(2) Supplementary written reports, prepared on AF Form 112, wlll be forwarded to the
Director of Intelligence, Headquarters United States Alr Force.
(3) Commanding General, Air Materiel Command ls authorized direct contact with major
Alr Commands (overseas) and organizations under their control in connection with the
development of information on this subject.
c. Major Air Commands (ZI)
(1) Reports wm be forwarded direct to the Commanding General, Air Materiel Command,
Wright-Patterson Air Force Base, Dayton, Ohio, Attn: MClAX0-3 by installations receiv­
ing information pertaining to the requirements enunciated in Part Il.
(2) Coples of such r eports may be supplied the Command Headquarters of the Installation
concerned.
(3) A copy of all reports sent to Air Materiel Command In accordance with these instr uc­
tions will be forwarded at the same time to the Director of Intelllgence, Headquarters
United States Air Force.
(4) Written reports will be submitted on AF Form 112.
(5) Commanding General, Air Materiel Command Ls authorized direct contact with major
Air Commands (ZI) and organizations under their control In connection with the develop­
ment of information on this subject.
d. Non-Air Force Agencies
(1) Addressees ot~er than those of the United States Air Force are requested to forward
reports direct to the Commanding General, Air Materiel Command, Wright-Patterson Air
Force Base, Dayton, Ohio, Attn: MCIAX0-3.
(2) In order to reduce the time factor involved in transmission of this type of information
Lt ls requested that, wherever communications facilities permit, subordinate elements be
authorized to communicate reports direct to the Commanding General, Air Materiel Com­
mand.
PART II - REQUIREMENTS
General
1. Date of sighting.
2. Time of sighting (zonal by 24 hr. clock).
3. Where sighted (observer's position):
a. Ground
(1) City, town.
(2) Distance and direction from city or town, r oad, intersection, etc.
(3) From building (story), yard, etc.
(4) Map coordinates (11 feasible) showing latitude and longitude.
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b, Air
(1)
Type a1rcraft, speed, alutude, d1rection of fUght.
(2) Distance and d1rection from city, town or known landmark.
(3) Clock posltlon of object from observer's aircraft.
(4) Latitude and longitude.
c. Sea
(1) Latitude and longitude.
(2)
Pr oximity to land.
(Name city, country, etc.)
4.
Number of objects.
Formation type (lf any), sketch 1f possible.
5. Observable celestlal phenomena or planets that may account for the sight1ng.
(Local £ac1Uties
or organizations which follow such celestial phenomena should be consulted for such Lnformatlon.)
6. Distance of object from observer.
a. Laterally or hor1zontally.
b. Angle of elevation from horizon.
c. Altitude.
7. Time in sight.
8. Appearance of object.
a. Color.
b. Shape.
(Sketch if possible)
c. Apparent construction.
(Of what material or substance)
d, Size,
(1)
Estimated size.
(2) Size as it appeared from observer's view.
(Compared to known object)
9. Direction of flight.
10. Tactics or maneuvers.
Vertical ascent or descent, horizontal, osclllatlng, fluttering, evasive, aggressive, erratic, etc.
11. Evidence of exhaust.
a. Color of smoke.
, b. Length and width.
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- 3 ­

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c. Odor (if any).
d. Rate of evaporation.
e. Does trail vary wl.th sound? (spurts)
12. Effect on clouds.
a. Opened path thru clouds.
b. Forced cloud or ml.sts.
c. Re.fleeted on cloud.
d. Showed thru cloud.
13. Llghts.
a. Reflected or attached.
b. Luminous
c. Blinked on and off in relation to speed.
14, Support
a. Wings.
b. Aerodynamic list of fuselage.
c. Vertical jet.
d. Rotating cylinder or cone.
e. Aerostatl.c lift (balloon or dirigible).
15. Propulsion.
a. Propeller or jet.
b. Rotor.
c. Aerodynamic vanes (flapping or oscillatlng) (Katz Mayer effect).
d. Visible exhaust or jet openings.
16. Control and stabllity.
a. Fins
b. Stabilizers (horizontal or vertical).
(1) Sl.ze.
(2) Shape.
(3)
Location.
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17. Air ducts.
a. Slots.
b. Duct openings.
18. Speed - M.P .H.
19. Sound.
a. Continuous whine or buzz.
b. Roar, whistle, whoosh.
c. Intermittent.
20. Manner of disappearance.
a.
Explode.
(1) Possibil!.ty of fragments.
(2) Other physical evidence.
b. Faded from view.
c. Disappeared behind obstacle.
Relat!.ve to the Observer
1. Name of observer.
2. Address.
3. Occupation.
4. Place of business.
a. Employer or employee.
5. Pertinent hobbies.
a. Is observer amateur astronomer, pilot, engineer, etc.
b. Length of time engaged in hobby (experience).
6. Ability to deter mine:
a. Color.
b. Speed of moving objects.
c. Size at distance.
7. Rellabillty of observer.
a.
Sources.
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- 5 -

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(1)
Neighbors.
(2) Police Dept.
(3) FBI records.
(4) Employer.
8. Notes relative to observer on:
a. Sightings in general.
b. How attention was drawn to object(s).
(1) Sound.
(2) Motion.
(3) Glint of light.
c. Degree of fatigue and duration of flight at time of slghtlng in cases where observer is
airborne.
9. Witnesses.
a. Addressees.
b. Occupation.
C.
ReUabiUty.
10. Comments of interrogator regarding the intelUgence and character of person inter rogated.
Relative to Radar Sightings
1. Re radars operating on ground.
a. Observations of range, speed, altitude and size of target.
b. Did target executive any turns? If so, what angle (180°), etc. and what radius of turn.
If radius of turn ls not observable, how long did the target stay in the turn and what was its speed?
c. Note particularly any separation of distant target Into several targets upon approach. Track
all if possible.
2. If airborne when object sighted.
a. Were there any radar inductions or extra noise on radio circuits?
b. Give estimates of size, speed, maneuvers, etc.
GENERAL
1. Teletype sequences of local weather condlt1ons.
2. Winds aloft report.
- 6 -
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S. Local flight schedules of commercial, private and military aircraft flying In vicinity at the
time.
(Check Canadian activity if close to that border.)
4. Possible releases of testing devices in vicinity sent aloft by Ordnance, Navy, Air Force,
Army, Weather Units, Research Organizations or any other.
6.
If object contacted earth, obtain soil samples within and without depression or spot where
object landed (and then presumably departed) for purpose of making comparison of soils.
6. If object came sufficiently near other aircraft or known objects check surfaces with Geiger
counters for possible radioactivity. Make comparisons with other unaffected aircrait objects, etc.
7. Obtain photographs (or original negatives) where available; if not, secure sketches of:
a. Object.
b. Surrounding terrain where observed.
c. Place where it contacted earth (if this happened).
d.
Maneuvers.
e. Formation 1f objects were more than two.
8. Secure signed statement.
9. Obtain fragments or physical evidence where possible.
10. Was any radio antenna to be observed, i.e., (any projections or extentlons that might presum­
ably be construed as such).
cf-?~
C. P. CABELL
Major General, USAF
Director of Intelllgence, Office of
Deputy Chief of Staff, Operations
DISTRIBUTION:
Commanding Generals, Major Air Commands,
ZI and overseas
All United States Air Attaches
Director of Central IntelUgence
Special Assistant for Research and Intelligence,
Department of State
Director o:f Intelllgence, GSUSA
Chief of Naval Intelligence
Commandant (!NT), United States Coast Guard
Director, Federal Bureau of Investigation
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RESTRICTED
I
I

RESTRICTED
DEPARTMENT OF THE AIR FORCE
HEADQUARTERS UNITED STATES AIR FORCE
DIRECTORATE OF INTELLIGENCE
WASHINGTON 25, D. C.
16 February 1949
AIR INTELLIGENCE REQUIREMENTS
MEMORANDUM NUMBER 4
UNCONVENTIONAL AIRCRAFT
PART I - GENERAL
1. PURPOSE
The purpose of this memorandum is twofold:
a. To enunciate continuing Air Force requirements for information pertaining to sightings of
unconventional aircraft and unidentified flying objects , including the so-called "Flying Discs."
b.
To establish procedures for reporting such information.
2. RESCISSION
Department of the Army CollecUon Memorandum Number 7, dated 21 January 1948, and letter,
CSGID 425.1, dated 25 March 1948, both subject as above, which have been transferred to Air
Force agencies for action, are herewith superseded.
3. REPORTING
a. General
(1) As complete an answer to the requirements enunciated in Part II, as may be procur­
able, should be dispatched by means of electrical transmission immediately after sightings.
(2) Supplementary reports should be forwarded as available by the most expeditious means
consistent with the importance of the information reported.
b. Major Air Commands (Overseas) and Air Attaches
(1) Initial and supplementary cabled reports will be transmitted to the Director of Intelli­
gence, Headquarters United States Air Force. Cables wm contain the phase, " Pass to
COMGENAMC WRIGHT-PATTERSON AFB, DAYTON, OHIO, ATTN: MCIAXO-3.''
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C9•11892,.4F

RES TRIC T ED
(2) Supplementary written reports, prepared on AF Form 112, will be forwarded to the
Director of Intelligence, Headquarters United States Air Force.
(3) Commanding General, Air Materiel Command is authorized direct contact wlth major
Air Commands (overseas) and organizations under their control in connection with the
development of information on this subject.
c. Major Air Commands (ZI)
(1) Reports wlll be forwarded direct to the Commanding General, Air Materiel Command,
Wright-Patterson Air Force Base, Dayton, Ohio, Attn: MCIAX0-3 by installations receiv­
ing information pertaining to the requirements enunciated in Part II.
(2) Copies of such r eports may be supplied the Command Headquarters of the installation
concerned.
(3) A copy of all reports sent to Air Materiel Command in accordance with these instruc­
tions will be forwarded at the same time to the Director of Intelligence, Headquarters
United States Air Force.
(4) Written r eports will be submitted on AF Form 112.
(5) Commanding General, Air Materiel Command ls authorized direct contact with major
Air Commands (ZI) and organizations under their contr ol in connection wlth the develop­
ment of information on this subject.
d. Non-Air Force Agencies
(1) Addressees ot~er than those of the United States Air Force are requested to forward
r eports direct to the Commanding General, Alr Materiel Command, Wright-Patterson Air
Force Base, Dayton, Ohio, Attn:
MCIAX0-3.
(2) In order to reduce the time factor involved in transmission of this type of information
it is requested that, wherever communications facilities permit, subordinate elements be
authorized to communicate reports direct to the Commanding General, Alr Materiel Com­
mand.
PART II - REQUIREMENTS
General
1. Date of sighting.
2. Time of sighting (zonal by 24 hr. clock).
3. Wher e sighted {observer's position):
a. Ground
(1) City, town.
(2) Distance and direction from city or town, road, intersection, etc.
(3)
From building (story), yard, etc.
(4) Map coordinates (if feasible) showing latitude and longitude.
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b. Air
(1) Type aircraft, speed, altitude, direction of flight.
(2) Distance and direction from city, town or known landmark.
(3) Clock position of object from observer's aircraft.
(4) Latitude and longitude.
c. Sea
(1) Latitude and longitude.
(2) Pr oximity to land. (Name city, country, etc.)
4. Number of objects.
Formation type (If any), sketch if possible.
5. Observable celestial phenomena or planets that may account for the sighting.
(Local faciUtles
or organizations which follow such celestial phenomena should be consulted for such information.)
6.
Distance of object from observer.
a. Laterally or horizontally.
b. Angle of elevation from horizon.
c. Altitude.
7.
Time in sight.
8.
Appearance of object.
a. Color.
b. Shape.
(Sketch If possible)
c. Apparent construction.
(Of what material or substance)
d. Size.
(1) Estimated size.
(2) Size as lt appeared from observer's view. (Compared to known object)
9. Dir ection of flight.
10. Tactics or maneuvers.
Vertical ascent or descent, horizontal, oscillating, fluttering, evasive, aggressive, erratic, etc.
11. Evidence of exhaust.
a. Color of smoke.
, b. Length and width.
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c. Odor (!.f any).
d. Rate of evaporation.
e. Does trail va:ry with sound?
(spurts)
12. Effect on clouds.
a. Opened path thru clouds.
b. Forced cloud or mists.
c. Reflected on cloud.
d. Showed thru cloud.
13. Lights.
a. Reflected or attached.
b. Luminous
c. Blmked on and off in relation to speed.
14. Support
a. Wings.
b. Aerodynamic 11st of fuselage.
c . Vertical jet.
d. Rotating cylinder or cone.
e. Aerostatic liit (balloon or dirigible).
15. Propulsion.
a. Propeller or jet.
b. Rotor.
c. Aerodynamic vanes (flapping or osclllating) (Katz Mayer effect).
d. Visible exhaust or jet openings.
16. Control and stability.
a. Fins
b. Stabilizers (horizontal or vertical).
(1) Size.
(2) Shape.
(3) Location.
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17. Air ducts .
a. Slots.
b.
Duct openings.
18. Speed - M.P .H.
19. Sound.
a. Continuous whine or buzz.
b. Roar, whistle, w};l.oosh.
c.
Intermittent.
20.
Manner of disappearance.
a.
Explode.
(1) PosslblUty of fragments.
(2) Other physical evidence.
b. Faded from view.
c. Disappeared behind obstacle.
Relative to the Observer
1. Name of observer .
2. Address.
3. Occupation.
4.
Place of business.
a. Employer or employee.
5. Pertinent hobbles.
a. Is observer amateur astronomer, pilot, engineer, etc.
b. Length of time engaged l.n hobby (experience).
6. Ablllty to determine:
a. Color .
b. Speed of moving objects.
c. Size at distance.
7. Reliability of observer.
a.
Sources.
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- 5 -

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(1) Neighbors.
(2) Police Dept.
(3) FBI records,
(4) Employer.
8. Notes relative to observer on:
a. Sightings in general.
b. How attention was drawn to object(s}.
(1) Sound.
(2) Motion.
(3) Glint of light.
c . Degree of fatigue and duration of flight at time of sighting in cases where observer is
airborne.
9. Witnesses.
a. Addressees.
b. Occupation.
c. Rellab1Uty.
10. Comments of interrogator regarding the intelllgence and character of person interrogated.
Relative to Radar Sightings
1. Re radars operating on ground.
a. Observations of range, speed, altitude and size of target.
b. Did target executive any turns? If so, what angle (180°), etc. and what radius of turn.
If radius of turn is not observable, how long did the target stay in the turn and what was its speed?
c. Note particularly any separation of distant target into several targets upon appr oach. Track
all Ii possible.
2. If airborne when object sighted.
a. Were there any radar inductions or extra noise on radio circuits?
b. Give estimates of size, speed, maneuvers, etc.
GENERAL
1. Teletype sequences of local weather conditions.
2. Winds aloft report.
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3. Local flight schedules of commercial, private and military aircraft flying 1n vicinity at the
time.
(Check Canadian activity If close to that border.)
4. Possible releases of testing devices in vicinity sent aloft by Ordnance, Navy, Air For ce,
Army, Weather Units, Research Organizations or any other.
6.
If object contacted earth, obtain sol.l samples within and without depr ession or spot where
object landed (and then presumably departed) for purpose of making comparison of soils.
6. If object came sufficiently near other aircraft or known objects check surfaces with Gelger
counters for possible radioactivity. Make comparisons with other unaffected aircraft objects, etc.
7. Obtain photographs (or original negatives) where available; 1f not, secure sketches of:
a. Object.
b. Surrounding terrain where observed.
c. Place where it contacted earth (lf this happened).
d. Maneuvers.
e. Formation if objects were more than two.
8. Secure signed statement.
9. Obtain fragments or physical evidence where possible.
10. Was any radio antenna to be observed, i.e., (any projections or extentions that might presum­
ably be construed as such).
C. P . CABELL
Major General, USAF
Director of Intelllgence, Office of
Deputy Chief of Sta.ff, Operations
DISTRIBUTION:
Commanding Generals, Major Air Commands,
ZI and Overseas
All United States Air Attaches
Director of Central Intelllgence
Special Assistant for Research and Intelligence,
Department of State
Director of Intelligence, GSUSA
Chief of Naval Intelllgence
Commandant (INT), United States Coast Guard
Director, Federal Bureau of Investlgatlon
RESTRICTED
- 7 ­

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RESTRICTED

RESTRICTED
DEPARTMENT OF THE AIR FORCE
HEADQUARTERS UNITED STATES AIR FORCE
DIRECTORATE OF INTELLIGENCE
WASHINGTON 25, D. C.
15 February 1949
AIR INTELLIGENCE REQUIREMENTS
MEMORANDUM NUMBER 4
UNCONVENTIONAL AIRCRAFT
PART I - GENERAL
1. PURPOSE
The purpose of this memorandum ls twofold:
a. To enunciate continuing Air Force requirements for information pertaining to sightings of
unconventional aircraft and unidentified flying objects, including the so~called "Flying Discs."
b. To establish procedures for reporting such information.
2. RESCISSION
Department of the Army Collectlon Memorandum Number 7, dated 21 January 1948, and letter,
CSGID 425.1, dated 25 March 1948, both subject as above, which have been transferred to Air
Force agencies for actlon, are herewith superseded.
3. REPORTING
a. General
(1)
As complete an answer to the requirements enunciated in Part II, as may be procur­
able, should be dispatched by means of electrical transmission immediately after sightings.
(2) Supplementary reports should be forwarded as available by the most expeditious means
consistent with the importance of the information reported.
b. Major Air Commands (Overseas) and Air Attaches
(1) Initial and supplementary cabled reports will be transmitted to the Director of Intelll­
gence, Headquarters United State:s Air Force. Cables will contain the phase, " Pass to
COMGENAMC WRIGHT-PATTERSON AFB, DAYTON, OHIO, ATTN: MCIAXO-3."
RESTRICTED

RESTRICTED
(2) Supplementary written reports, prepared on AF Form 112, will be forwarded to the
Director of Intelligence, Headquarter s United States Air Force.
(3) Commanding General, Air Materiel Command is authorized direct contact with major
Air Commands (overseas) and organizations under their control in connection with the
development of information on this subject.
c. Major Alr Commands (ZI)
(1) Reports will be forwarded direct to the Commanding General, Air Materiel Command,
Wright-Patterson Air Force Base, Dayton, Ohio, Attn: MCIAX0-3 by Installations receiv­
ing information pertaining to the requirements enunciated in Part II.
(2) Coples of such r eports may be supplied the Command Headquarters of the installation
concerned.
(3) A copy of all reports sent to Air Materiel Command in accordance with these instruc­
tions will be forwarded at the same time to the Director of Intelllgence, Headquarters
United States Air Force.
(4) Written reports will be submitted on AF Form 112.
(5) Commanding General, Air Materiel Command ls authorized direct contact with major
Air Commands (ZI) and organizations under their control in connection with the develop­
ment of information on this subject .
d.
Non-Air Force Agencies
(1) Addressees otqer than those of the United States Air Force are requested to forward
reports direct to the Commanding General, Air Materiel Command, Wright-Patterson Air
Force Base, Dayton, Ohio, Attn: MCIAX0-3.
(2) In order to reduce the tlme factor involved 1n transmission of this type of information
it ls requested that, wherever communications facilities permit, subordinate elements be
authorized to communicate reports direct to the Commanding General, Air Materiel Com­
mand.
PART Il - REQUIREMENTS
General
1. Date of sighting.
2.
Time of sighting (zonal by 24 hr. clock).
3. Wher e sighted (observer's position):
a. Ground
(1) City, town.
(2) Distance and direction from city or town, road, Intersection, etc.
(3) From building (story), yard, etc .
(4) Map coordinates (if feasible) showing latitude and longitude.
- 2 -
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b, Air
(1) Type aircraft, speed, altitude, direction of flight.
(2) Distance and direction fr om city, town or known landmark.
(3) Clock position of object from observer's aircraft.
(4) Latltude and longitude.
c. Sea
(1) Latitude and longitude.
(2)
Proximity to land.
(Name city, country, etc.)
4. Number of objects.
Formation type (!f any), sketch if possible.
5. Observable celestial phenomena or planets that may account for the sighting.
(Local facllitles
or organizations which follow such celestial phenomena should be consulted for such information.)
6. Distance of object from observer.
a. Laterally or horizontally.
b. Angle of elevation from horizon.
c. Altitude.
7. Tl.me 1n sight.
8. Appearance of object.
a. Color.
b. Shape.
(Sketch if possible)
c. Apparent construction.
(Of what material or substance)
d. size.
(1) Estimated size.
(2) Size as it appeared from observer's view. (Compared to known object)
9. Dir ection of flight.
10. Tactics or maneuvers.
Vertical ascent or descent, horizontal, osclllating, fluttering, evasive, aggressive, er ratic, etc.
11. Evidence of exhaust.
a. Color of smoke.
, b. Length and width.
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- 3 ­

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c.
Odor (if any).
d. Rate of evaporation.
e. Does trall vary with sound?
(spurts)
12. Effect on clouds.
a.
Opened path thru clouds.
b.
Forced cloud or mists.
c. Reflected on cloud.
d. Showed thru cloud.
13. Lights.
a. Reflected or attached.
b.
Luminous
c. Bllnked on and off l.n relation to speed.
14. Support
a. Wings.
b.
Aerodynamic list of fusel~e.
c. Vertical jet.
d.
Rotating cylinder or cone.
e. Aerostatic lift (balloon or dirigible).
15. Propulsion.
a.
Propeller or jet.
b.
Rotor.
c. Aerodynamlc vanes (flapping or oscUlating) (Katz Mayer effect).
d. Visible exhaust or jet openings.
16. Control and stability.
a. Fins
b.
StabiHzers (horizontal or vertical).
(1) Size.
(2) Shape.
(3) Location.
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RESTRIC TED
17. Air ducts.
a. Slots.
b. Duct openlngs.
18. Speed - M.P.H.
19. Sound.
a. Contlnuous whine or buzz.
b. Roar, whistle, whoosh.
c. Intermittent.
20. Manner of disappearance.
a. Explode.
(1) Possibility of fragments.
(2)
Other physical evidence.
b.
Faded from view,
c.
Disappeared behind obstacle.
Relative to the Observer
1.
Name of observer.
2. Address.
3. Occupation.
4. Place of business.
a.
Employer or employee.
5.
Pertinent hobbies.
a. Is observer amateur astronomer, pilot, engineer, etc.
b. Length of time engaged in hobby (experience).
6. Ability to determine:
a.
Color.
b. Speed of moving objects.
c. Size at distance.
7.
Re11ab111ty of observer.
a.
Sources.
REST RICTED
- 5 -

RESTRICTED
(1) Neighbors.
(2) Police Dept.
(3)
FBI records.
(4) Employer.
8.
Notes relative to observer on:
a. Sightings in general.
b. How attention was drawn to oblect(s).
(1) Sound.
(2) Motion.
(3) Glint of light.
c. Degree of fatigue and duration of flight at time of sighting ln cases where observer is
airborne.
9. Witnesses.
a. Addressees.
b.
Occupation.
c. Rell.ability.
10. Comments of interrogator regarding the lntelHgence and character of person interrogated.
Relative to Radar Sightings
1. Re radars operating on ground.
a. Observations of range, speed, altitude and size of target.
b. Did target executive any turns? If so, what angle (180°), etc. and what radius of turn.
If radius of turn ls not observable, how long did the target stay in the turn and what was I.ts speed?
c. Note particularly any separation of distant target into several targets upon approach. Track
all 1f possible.
2. If airborne when object sighted.
a. Were there any radar inductions or extra noise on radio circuits?
b. Give estimates of size, speed, maneuvers, etc.
GENERAL
1. Teletype sequences of local weather conditions.
2. Winds aloft report.
- 6 -
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RESTRICTED
3. Local flight schedules of commercial, private and m111tary aircraft flylng ln vicinlty at the
tlme.
(Check Canadian activity 1f close to that border.)
4. Possible releases of testing devices 1n vicinity sent aloft by Ordnance, Navy, Air Force,
Army, Weather Units, Research Organizations or any other.
5. If object contacted earth, obtain soil samples within and without depression or spot where
object landed (and then presumably departed) for purpose of making comparison of sons.
6.
If object came sufficiently near other aircraft or known objects check surfaces with Gelger
counters for possible radioactivity. Make comparisons with other unaffected aircraft objects, etc.
7. Obtain photographs (or original negatives) where available; if not, secure sketches of:
a . Object.
b. Surrounding terrain where observed.
c. Place where it contacted earth (if this happened).
d. Maneuvers.
e. Formation 1f objects were more than two.
8. Secure signed statement,
9. Obtain fragments or physical evidence where possible.
10. Was any radlo antenna to be observed, Le., (any projections or extentions that might presum­
ably be construed as such).
c.P~
C. P. CABELL
Major General, USAF
Director of IntelUgence, Office of
Deputy Chief of Staff, Operations
DISTRIBUTION:
Commanding Generals, Major Air Commands,
ZI and Overseas
All United States Air Attaches
Director of Central Intelligence
Special Assistant for Research and Intelligence,
Department of State
Director of Intelligence, GSUSA
Chief of Naval Intelligence
Commandant (INT), United States Coast Guard
Director, Federal Bureau of Investigation
AESTRICTED
- 7 -

RESTRICTED
RESTRICTED

RESTRICTED
DEPARTMENT OF THE AIR FORCE
HEADQUARTERS UNITED STATES AIR FORCE
DIRECTORATE OF INTELLIGENCE
WASHINGTON 25, D. C.
15 February 1949
AIR INTELLIGENCE REQUIREMENTS
MEMORANDUM NUMBER 4
UNCONVENTIONAL AIRCRAFT
PART I - GENERAL
1. PURPOSE
The purpose of this memorandum ls twofold:
a. To enW1ciate continuing Alr Force requirements for information pertaining to sightings of
Wlconventlonal aircraft and Wlidentified flying objects, including the so-called "Flying Discs."
b. To establish procedures for reporting such informatlon.
2. RESCISSION
Department of the Army Collection Memorandum Number 7, dated 21 January 1948, and letter,
CSGID 425.1, dated 25 March 1948, both subject as above, which have been transferred to Air
Force agencies for action, are herewith superseded.
3. REPORTING
a.
General
(1) As complete an answer to the requirements enW1ciated in Part II, as may be procur­
able, should be dispatched by means of electrical transmission immediately after sightings.
(2) Supplementary reports should be forwarded as available by the most expeditious means
consistent with the importance of the information reported.
b. Major Air . Commands (Overseas) and Air Attaches
(1) Initial and supplementary cabled reports will be transmitted to the Director of Intelli­
gence, Headquarters United State:s Air Force. Cables wUl contain the phase, "Pass to
COMGENAMC WRIGHT-PATTERSON AFB, DAYTON, OHIO, ATTN: MClAX0-3."
RESTRICTED

RESTRICTED
(2) Supplementary written reports, prepared on AF Form 112, will be forwarded to the
Director of Intelligence, Headquarters United States Air Force.
(3) Commanding General, Air Materiel Command is authorized direct contact wlth major
Air Commands (overseas) and organizations under their control in connection with the
development of in.formation on this subject.
c. Major Air Commands (ZI)
(1) Reports wm be forwarded direct to the Commanding General, Air Materiel Command,
Wright-Patterson Air Force Base, Dayton, Ohio, Attn: MCIAX0-3 by installations receiv­
ing information pertaining to the requirements enunciated in Part II.
(2) Coples of such reports may be supplled the Command Headquarters of the installation
concerned.
(3) A copy of all reports sent to Air Materiel Command in accordance with these instruc­
tions will be forwarded at the same time to the Director of Intelligence, Headquarters
United States Air Force.
(4)
Written reports will be submitted on AF Form 112.
(5) Commanding General, Air Materiel Command is authorized direct contact with major
Air Commands (ZI) and organizations under their control in connectlon with the develop­
ment of information on this subject.
d. Non-Air Force Agencies
(1) Addressees otQer than those of the United States Air Force are requested to forward
reports direct to the Commanding General, Air Materiel Command, Wright-Patterson Air
Force Base, Dayton, Ohio, Attn: MCIAX0-3.
(2) In order to reduce the time factor involved in transmission of this type of information
it is r equested that, wherever communications facilities permit, subordinate elements be
authorized to communicate reports direct to the Commanding General, Air Materiel Com­
mand.
PART ll - REQUIREMENTS
General
1. Date of sighting.
2. Time of sighting (zonal by 24 hr. clock).
3. Where sighted (observer's position):
a. Ground
(1) City, town.
(2) Distance and direction from city or town, road, intersection, etc.
(3) From building (story), yard, etc.
(4)
Map coordinates (if feasible) showing latitude and longitude.
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b , Air
(1)
Type aLrcraft, speed, altltude, direction of fllght.
(2)
Distance and direction from city, town or known landmark.
(3)
Clock positlon of object from observer's aircraft.
(4) Latitude and longitude.
c. Sea
(1) Latitude and longitude.
(2) Proximity to land.
(Name city, country, etc.)
4. Number of objects.
Formation type (1! any), sketch if possible.
5. Observable celestial phenomena or planets that may account for the sighting.
(Local facilities
or organizations which follow such celestial phenomena should be consulted for such information.)
6.
Distance of object from observer.
a. Laterally or horizontally.
b. Angle of elevation from horizon.
c. Altitude.
7. Time in sight.
8, Appearance of object.
a. Color.
b. Shape.
(Sketch if posslble)
c. Apparent constructlon.
(Of what material or substance)
d. Size.
(1) Estimated slze.
(2) Size as it appeared from observer's view. (Compared to known object)
9. Direction of fllght.
10. Tactics or maneuvers.
Vertical ascent or descent, horizontal, osclllat1ng, fluttering, evasive, aggressive, erratic, etc.
11. Evidence of exhaust.
a.
Color of smoke.
1 b. Length and width.
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•

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C.
Odor (1.f any).
d. Rate of evaporation.
e. Does trail vary wlth sound?
(spurts)
12. Effect on clouds.
a. Opened path thru clouds.
b. Forced cloud or mists.
c. Reflected on cloud.
d. Showed thru cloud.
13. Lights.
a. Reflected or attached.
b. Lumlnous
c. Blinked on and off ln relation to speed.
14. Support
a. Wings.
b. Aerodynamic list of fuselage.
c. Vertical jet.
d. Rotating cylinder or cone.
e . Aerostatlc llit (balloon or dlr1glble).
16. Propulsion.
a. Propeller or jet.
b. Rotor.
c. Aerodynamic vanes (flapping or oscillating) (Katz Mayer effect).
d. Visible exhaust or jet openings.
16. Control and stability.
a. Fins
b. Stab111zers (horizontal or vertical).
(1) Size.
(2) Shape.
(3) Location.
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17. Air ducts.
a. Slots.
b. Duct openings.
18. Speed - M.P.H.
19. Sound.
a. Continuous whlne or buzz.
b. Roar I whistle, wooosh.
c. Intermittent.
20. Manner of disappearance.
a.
Explode.
(1) Possibility of fragments.
(2) Other physical evidence.
b.
Faded from view.
c. Disappeared behind obstacle.
Relatlve to the Observer
1. Name of observer.
2.
Address.
3.
Occupation.
4. Place of buslness.
a. Employer or employee.
5.
Pertinent hobbies.
a. Is observer amateur astronomer, pilot, engineer, etc.
b. Length of time engaged in hobby (experience).
e.
Ability to determine:
a. Color.
b. Speed of moving objects.
c. Size at distance.
7. Reliability of observer.
a.
Sources.
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(1)
Neighbors.
(2) Police Dept.
(3) FBI records.
(4) Employer.
8. Notes relative to observer on:
a. Sightings in general.
b. How attention was drawn to object(s).
(1) Sound.
(2) Motion.
(3) Glint of light.
c. Degree of fatigue and duration of flight at time of sighting in cases where observer is
airborne.
9. Witnesses.
a. Addressees.
b. Occupation.
c. Reliability.
10. Comments of interrogator regarding the intelligence and character of person interrogated.
Relative to Radar Sightings
1. Re radars operating on ground.
a. Observations of range, speed, altitude and size of target.
b. Did target executive any turns? If so, what angle (180°), etc. and what radius of turn.
If radius of turn is not observable, how long did the target stay in the turn and what was its speed?
c . Note particularly any separation of distant target into several targets upon approach. Track
all Ii possible.
2. If airborne when object sighted.
a. Were there any radar inductions or extra noise on radio circuits?
b. Give estimates of size, speed, maneuvers, etc.
GENERAL
1. Teletype sequences of local weather conditions.
2. Winds aloft report.
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3. Local flight schedules of commercial, private and m.111tary aircraft flying In vicinity at the
time.
(Check Canadian activity 1f close to that border.)
4. Possible releases of testing devices 1n vicinity sent aloft by Ordnance, Navy, Air For ce,
Army, Weather Units, Research Organizations or any other.
6.
If object contacted earth, obtain son samples within and without depression or spot where
object landed (and then presumably departed) for purpose of ma.king comparison of soils.
6. 11 object came sufficiently near other aircraft or known objects check surfaces with Geiger
counters for possible radioactivity. Make comparisons with other unaffected aircraft objects, etc.
7. Obtain photographs (or original negatives) where available; if not, secure sketches of:
a. Object.
b. Surrounding terrain where observed.
c. Place wher e it contacted earth (1.f this happened).
d.
Maneuvers.
e. Formation if objects were more than two.
8. Secure signed statement.
9. Obtain fragments or physical evidence where possible.
10. Was any radio antenna to be observed, Le., (any projections or extentlons that might presum­
ably be construed as such).
C. P . CABELL
Major General, USAF
Director of Intelligence, Office of
Deputy Chief of Staff, Operations
DISTRlBUTION:
Commanding Generals, Major Alr Commands ,
ZI and overseas
All United States Air Attaches
Director of Central Intelligence
Special Assistant for Research and Intelllgence,
Department of State
Director of Intelligence, GSUSA
Chief of Naval Intelllgence
Commandant (INT), United States Coast Guard
Director, Federal Bureau of Investigation
RES TRI CT ED
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DEPARTMENT OF THE Affi FORCE
HEADQUARTERS UNITED STATES AIR FORCE
DmECTORATE OF INTELLIGENCE
WASHINGTON 26, D. C.
15 Febr uary Hl49
AIR INTELLIGENCE REQUIREMENTS
MEMORANDUM NUMBER 4
UNCONVENTIONAL Am.CRAFT
PART I - GENERAL
1. PURPOSE
The purpose of this memorandum is twofold:
a. To enunciate continuing Air Force requirements for information pertaining to sightings of
unconventional aircraft and unidentified flying objects, including the so-called "Flying Discs.''
b. To establlsh procedures for reporting such information.
2. RESCISSION
Department of the Army Collection Memorandum Number 7, dated 21 January 1948, and letter,
CSGID 425.1, dated 25 March 1948, both subject as above, which have been transferred to Air
Force agencies for action, are herewith superseded.
3.
REPORTING
a.
General
(1)
As complete an answer to the requirements enunciated in Part II, as may be procur­
able, should be dispatched by means of electrical transmission immediately after sightings.
(2)
Supplementary reports should be forwarded as available by the most expeditious means
consistent with the importance of the information reported.
b. Major Air Commands (Overseas) and Air Attaches
(1) Initial and supplementary cabled reports will be transmitted to the Dir ector of Intelli­
gence, Headquarters United Statc,s Air Force. Cables wm contain the phase, "Pass to
COMGENAMC WRIGHT-PATTERSON AFB, DAYTON, OHIO, ATTN: MCIAX0-3."
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C9•11892,AF
b ~ - ff 1t- 9~-/t''/

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(2) Supplementary written reports, prepared on AF Form 112, wlll be forwarded to the
Director of Intelll.gence, Headquarters United States Air Force.
(3) Commanding General, Air Materiel Command ls authorized direct contact WI.th major
Air Commands (overseas) and organlzatl.ons under their control ln connection with the
development of information on this subject.
c. Major Air Commands (ZI)
(1) Reports will be forwarded direct to the Commanding General, Air Materiel Command,
Wright-Patterson Air Force Base, Dayton, Ohio, Attn:
MCIAX0-3 by installations r eceiv­
ing information pertaining to the r equir ements enunciated in Part II.
(2) Copies of such r eports may be supplied the Command Headquarter s of the installation
concerned.
(3) A copy of all reports sent to Air Materiel Command in accordance with these instruc­
tions wlll be forwarded at the same ti.me to the Director of Intelligence, Headquarters
United States Air Force.
(4) Written r eports wlll be submitted on AF Form 112.
(6) Commanding General, Air Materiel Command is authorized direct contact with major
Air Commands (Zl) and organizations under their control ln connection with the develop­
ment of information on this subject.
d.
Non-Air Force Agencies
(1) Addressees ot~er than those of the United States Air Force are r equested to forward
reports direct to the Commanding General, Air Materiel Command, Wright-Patterson Air
Force Base, Dayton, Ohio, Attn: MCIAX0-3.
(2) In order to r educe the ti.me factor involved in transmission of this type of information
it is requested that, wher ever communications facilities permit, subordinate elements be
authorized to communicate reports direct to the Commanding General, Air Materiel Com­
mand.
PART II - REQUIB.EMENTS
General
1. Date of sighting.
2. Tl.me of sighting (zonal by 24 hr. clock).
3. Where sighted (observer 's position):
a. Ground
(1) City, town.
(2) Distance and direction from city or town, r oad, intersection, etc.
(3) Fr om building (story), yard, etc.
(4) Map coordinates (if feasible) showing latitude and longitude.
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b. Air
(1) Type aircraft, speed, altitude, direction of flight.
(2) Distance and dlrectlon from city, town or known landmark.
(3) Clock position of object from observer's aircraft.
(4) Latitude and longitude.
c. Sea
(1) Latitude and longitude.
(2)
Proximity to land.
(Name city, country, etc.)
4.
Number of objects.
Formation type (Lf any), sketch if possible.
5. Observable celestial phenomena or planets that may account for the sighting. (Local facilities
or organizations which follow such celestial phenomena should be consulted for such information.)
6. Distance of object from observer.
a. Laterally or horizontally.
b. Angle of elevation from horizon.
c. Altitude.
7. Time 1n sight.
8. Appearance of object.
a. Color.
b. Shape.
(Sketch if possible)
c. Apparent construction.
(Of what material or substance)
d. Size.
(1)
Estimated size.
(2) Size as it appeared from observer's view. (Compared to known object)
9. Direction of flight.
10. Tactics or maneuvers.
Vertical ascent or descent, horizontal, oscillating, fluttering, evasive, aggressive, erratic, etc.
11. Evidence of exhaust.
a. Color of smoke.
, b. Length and width.
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- 3 ­

RESTRIC TE D
C.
Odor (if any).
d. Rate of evaporation.
e. Does trall vary with sound?
(spurts)
12. Effect on clouds.
a.
Opened path thru clouds.
b.
Forced cloud or mists .
c. Reflected on cloud.
d. Showed thru cloud.
13. Lights.
a.
Reflected or attached.
b.
Luminous
c.
Bllnked on and off in relation to speed.
14. Support
a. Wings.
b.
Aerodynamic list of fuselage.
c. Vertical jet.
d.
Rotating cylinder or cone.
e.
Aerostatic lift (balloon or dirigible).
15. Pr opulsion.
a.
Propeller or jet.
b.
Rotor .
c.
Aerodynamic vanes (flapping or oscillating) (Katz Mayer effect).
d. Vlslble exhaust or jet openings.
16.
Control and stability.
a. Fins
b.
Stabilizers (hor izontal or vertical).
(1) Size.
(2) Shape.
(3) Location.
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17. Air ducts.
a. Slots.
b. Duct openings.
18. Speed - M.P.H.
19. Sound.
a. Continuous whine or buzz.
b. Roar, whistle, whoosh.
C.
Intermittent.
20.
Manner of disappearance.
a. Explode.
(1) Possib111ty of fragments.
(2) Other physical evidence.
b. Faded from view.
c. Disappeared behind obstacle.
Relative to the Observer
1. Name of observer.
2. Address.
3.
Occupation.
4. Place of business.
a. Employer or employee.
5. Pertinent hobbies.
a. Is observer amateur astronomer, pUot, engineer, etc.
b. Length of time engaged in hobby (experience).
6.
Abllity to determine:
a. Color.
b. Speed of moving objects.
c . Size at distance.
7. Rellabllity of observer.
a.
Sources.
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- 5 -

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(1) Neighbors.
(2) Police Dept.
(3)
FBI records.
(4) Employer.
8. Notes relative to observer on:
a. Sightings in general.
b. How attention was drawn to object(s).
(1) Sound.
(2) Motion.
(3) Glint of light.
c. Degree of fatigue and duration of flight at time of sighting in cases where observer is
airborne.
9. Witnesses.
a. Addressees.
b. Occupation.
c. Reliability.
10. Comments of interrogator regarding the Lnte111gence and character of person interrogated.
Relative to Radar Sightings
1. Re radars operating on ground.
a. Observations of range, speed, altitude and size of target.
b. Did target executive any turns? If so, what angle (180°), etc. and what radius of turn.
If radius of turn is not observable, how long did the target stay 1n the turn and what was its speed?
c. Note particularly any separation of distant target into several targets upon approach. Track
all 1f possible.
2. If airborne when object sighted.
a. Were there any radar inductions or extra noise on radio circuits?
b. Give estimates of size, speed, maneuvers, etc.
GENERAL
1. Teletype sequences of local weather conditions.
2. Winds aloft report.
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3. Local flight schedules of commercial, private and military aircraft flying in vic1n1ty at the
tlme.
(Check Canadian activity 1f close to that border.)
4. Possible releases o:f testing devices in vicinity sent aloft by Ordnance, Navy, Air Force,
Army, Weather Units, Research Organizations or any other.
6. If object contacted earth, obtain son samples within and without depression or spot where
object landed (and then presumably departed) for purpose of making comparison of soils.
6. If object came sufficiently near other aircraft or known objects check surfaces with Geiger
counters :for possible radioactivity. Make comparisons with other unaffected aircraft objects, etc.
7. Obtain photographs (or original negatives) wher e available; if not, secure sketches of:
a. Object.
b. Surrounding terrain where observed.
c. Place where it contacted earth (1:f this happened).
d. Maneuvers.
e. Formation 1:f objects were more than two.
8. Secure signed statement.
9. Obtain fragments or physical evidence where possible.
10. Was any radio antenna to be observed, Le., (any pr ojections or extentions that might presum­
ably be construed as such).
e>:P~
C. P. CABELL
Major General, USAF
Director of IntelUgence, Office of
Deputy Chief of Staff, Operations
DISTRIBUTION:
Commanding Generals, Major Air Commands,
ZI and Overseas
All United States Air Attaches
Director of Central Intelligence
Special Assistant for Research and Intelllgence,
Department of State
Director of Intelligence, GSUSA
Chief of Naval Intelligence
Commandant (I.NT), United States Coast Guard
Director, Federal Bureau of Investigation
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DEPARTMENT OF THE Am FORCE
HEADQUARTERS UNITED STATES Am FORCE
DmECTORATE OF INTELLIGENCE
WASHINGTON 25, D. C.
15 February 1949
AIR INTELLIGENCE REQUIREMENTS
MEMORANDUM NUMBER 4
UNCONVENTIONAL AIRCRAFT
PART I - GENERAL
1. PURPOSE
The purpose of this memorandum is twofold:
a. To enunciate continuing Air Force requirements for information pertaining to sightings of
unconventional aircraft and unidentifled flying objects, including the so-called "Flying Discs."
b. To establish procedures for reporting such information.
2. RESCISSION
Department of the Army Collection Memorandum Number 7, dated 21 January 1948, and letter,
CSGID 425.1, dated 25 March 1948, both subject as above, which have been transferred to Air
Force agencies for action, are herewith superseded.
3. REPORTING
a. General
(1) As complete an answer to the requirements enunciated in Part II, as may be procur­
able, should be dispatched by means of electrical transmission immediately after sightings.
(2) Supplementary reports should be forwarded as available by the most expeditious means
consistent with the importance of the informaUon reported.
b. Major Air Commands (Overseas) and Air Attaches
(1) Initial and supplementary cabled reports will be transmitted to the Director of Intelli­
gence, Headquarters United States Air Force. Cables will contain the phase, "Pass to
COMGENAMC WRIGHT-PATTERSON AFB, DAYTON, OHIO, ATTN:
MCIAX0-3."
RESTRICTED
C9·'892,AF

RESTRICTED
(2) Supplementary written reports, prepared on AF Form 112, wlll be forwarded to the
Director of Intelligence, Headquarters United States Alr Force.
(3) Commanding General, Air Materiel Command ls authorized direct contact with major
Alr Commands (overseas) and organizations under their control ln connection wlth the
development of information on this subject.
c. Major Air Commands (ZI)
(1) Reports will be forwarded direct to the Commanding General, Alr Materiel Command,
Wright-Patterson Air Force Base, Dayton, Ohio, Attn: MCIAXO-3 by installations receiv­
ing information pertaining to the r equirements enunciated in Part II.
(2) Copies of such r eports may be supplied the Command Headquarters of the installation
concerned.
(3) A copy of all reports sent to Air Materiel Command ln accordance with these instruc­
tions will be forwarded at the same tlme to the Director of Intelllgence, Headquarters
United States Air Force.
(4) Written r eports wlll be submitted on AF Form 112.
(5) Commanding General, Air Materiel Command is authorized direct contact with major
Air Commands (ZI) and organizations under their control in connection with the develop­
ment of information on this subject.
d.
Non-Alr Force Agencies
(1) Addressees ot~er than those of the United States Air Force are requested to forward
reports direct to the Commanding General, Air Materiel Command, Wright-Patterson Air
Force Base, Dayton, Ohio, Attn: MCIAXO-3.
(2) In order to reduce the time factor involved in transmission of this type of information
it is requested that, wher ever communications facilities permit, subordinate elements be
authorized to communicate reports direct to the Commanding General, Air Materiel Com­
mand.
PART II - REQUIREMENTS
General
1. Date of sighting.
2. Time of sighting (zonal by 24 hr. clock).
3. Where sighted (observer's position):
a. Ground
(1) City, town.
(2) DI.stance and direction from city or town, road, intersection, etc.
(3) From building (story), yard, etc.
(4) Map coordinates (l.f feasible) showing latitude and longitude.
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b. Air
(1) Type aircraft, speed, altitude, direction of flight.
(2) Distance and direction from city, town or known landmark.
(3) Clock posltlon of object from observer's aircraft.
(4) Latitude and longitude.
c. Sea
(1) Latitude and longitude.
(2) Proximity to land.
(Name city, country, etc.)
4. Number of objects.
Formation type (if any), sketch if possible.
5. Observable celestial phenomena or planets that may account for the sighting.
(Local facilities
or organizations which follow such celestial phenomena should be consulted for such information.)
6. Distance of object from observer.
a. Laterally or horizontally.
b. Angle of elevation from horizon.
c. Altitude.
7. Time in sight.
8. Appearance of object.
a. Color.
b. Shape.
(Sketch 1f possible)
c. Apparent construction.
(Of what material or substance)
d. Size.
(1) Estimated size.
(2) Size as it appeared from observer's view. (Compared to known object)
9, Direction of flight.
10. Tactics or maneuvers.
Vertical ascent or descent, horizontal, oscl.llating, fluttering, evasive, aggressive, erratic, etc.
11. Evidence of exhaust.
a. Color of smoke.
, b. Length and width,
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•

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c. Odor (1f any).
d. Rate of evaporation.
e. Does trail vary with sound?
(spurts)
12. Effect on clouds.
a. Opened path thru clouds.
b. Forced cloud or mists.
C. Reflected on cloud.
d. Showed thru cloud.
13. Lights.
a . Reflected or attached.
b. Luminous
c. Blinked on and off in r elation to speed.
14. Support
a. Wings.
b. Aerodynamic list of fuselage.
I
c. Vertical jet.
d. Rotating cylinder or cone.
e. Aerostatic lift (balloon or dirigible).
15. Propulsion.
a. Propeller or jet.
b. Rotor.
c . Aerodynamic vanes (flapping or oscillating) (Katz Mayer effect).
d. Visible exhaust or jet openings.
16. Contr ol and stability.
a. Fins
b. Stabilizers (horizontal or vertical).
(1) Size.
(2) Shape.
(3)
Location.
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17. Alr ducts.
a. Slots.
b. Duct openings.
18. Speed - M.P.H.
19. Sound.
a. Continuous whine or buzz.
b. Roar, whistle, wl;loosh.
C.
Intermittent.
20. Manner of disappearance.
a.
Explode.
(1)
Posslblllty of fragments.
(2) Other physical evidence.
b. Faded from view.
c. Disappeared behind obstacle.
Relative to the Observer
1. Name of observer.
2. Address.
3.
Occupation.
4. Place of business.
a. Employer or employee.
5. Pertinent hobbles.
a. Is observer amateur astronomer , pilot, engineer, etc.
b. Length of time engaged in hobby (experience).
6. Abllity to determine:
a. Color.
b. Speed of moving objects.
c. Size at distance.
7. ReliabiUty of observer.
a. Sources.
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(1) Neighbors.
(2) PoUce Dept.
(3) FBI r ecords.
(4) Employer.
8. Notes relative to observer on:
a. Sightings 1n general.
b. How attention was drawn to object(s).
(1) Sound.
(2) Motion.
(3) Glint of light.
c. Degree of fatigue and duration of flight at time of sighting in cases where observer is
airborne.
9. Witnesses.
a. Addressees.
b.
Occupation.
c.
Reliab1Uty.
10. Comments of interrogator regarding the intelllgence and character of person interrogated.
Relative to Radar Sightings
1. Re radars operating on ground.
a. Observations of range, speed, altitude and size of target.
b. Did target executive any turns? If so, what angle (180°), etc. and what radius of turn.
If radius of turn is not observable, how long did the target stay in the turn and what was 1ts speed?
c. Note particularly any separation of distant target into several targets upon approach. Tr ack
all 1f possible.
2. If airborne when object sighted.
a. Were there any radar inductions or extra noise on radio circuits?
b. Glve estimates of size, speed, maneuvers, etc.
GENERAL
1. Teletype sequences of local weather conditions.
2. Winds a.loft report.
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3. Local flight schedules of commercial, private and m111tary a1rcra!t flying in vicinity at the
time.
(Check Canadian activity 1f close to that border.)
4. Possible releases of testing devices 1n vicinity sent aloft by Ordnance, Navy, Air Force,
Army, Weather Units, Research Organizatlons or any other.
5. If object contacted earth, obtain soil samples within and without depression or spot where
object landed (and then presumably departed) for purpose of making comparison of solls.
6. I! object came sufficiently near other aircraft or known objects check surfaces with Gelger
counters for possible radioactivity. Make comparisons with other unaffected alrcr att objects, etc.
7. Obtain photographs (or original negatives) where available; if not, secure sketches of:
a. Object.
b. Surrounding terrain where observed.
c. Place wher e it contacted earth (if this happened).
d. Maneuvers.
e. Formation 1f objects were more than two.
8. Secure s igned statement.
9.
Obtain fragments or physical evidence where possible.
10. Was any radio antenna to be observed, Le., (any projections or extentions that might presum­
ably be construed as such),
c l?~
C. P. CABELL
Major General, USAF
Director of IntelHgence, Office of
Deputy Chief of Sta!f, Operations
DISTRIBUTION:
Commanding Generals, Major Air Commands,
ZI and Overseas
All United States Air Attaches
Director of Central Intell1gence
Special Assistant for Research and Intelllgence,
Department of State
Director of IntelHgence, GSUSA
Chief of Naval Intelligence
Commandant (INT), United States Coast Guard
Director, Federal Bureau of Investigation
RESTRI CT ED
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