65_HS1-834228961_62-HQ-83894_Serial_164 Serial 164 — copy of USAF Air Intelligence Requirements Memorandum No. 4, 'Unconventional Aircraft,' dated 15 February 1949 (DECLASSIFIED), establishing standardized Air Force reporting procedures and detailed observer-questionnaire requirements for sightings of unconventional aircraft and 'Flying Discs,' superseding Army Collection Memo No. 7 (Jan 1948); plus an Aug 1947 ADC report on the Alpheus O. Powell Pan Am Constellation sighting near Boston.
Air Intelligence Requirements Memo No. 4 has been previously declassified and circulated among UFO researchers and is part of the FBI Vault 62-HQ-83894 holdings; this 2026 release likely contains the same document with reduced redactions.
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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 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 256 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Force agencies for action, are herewith superseded.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.
) Supplementary reports should be forwarded as available by the most expeditious means
consistent with the importance of the information reported.
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: MCIAXO-3.”
L6t
. NC‘.OC"‘WE
RESTRICTED €9-4892,
AF
. RESTRICTED
(2) Supplementary written reports, prepared on AF Form 112, will be forwarded to the
Director of Intelligence, Headquarters United States Air Force.
(8) 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.
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.
(8) 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.
Non-Air Force Agencies
(1) Addressees other 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
Date of sighting.
Time of sighting (zonal by 24 hr. clock).
Where sighted (observer’s position):
a. Ground
(1) City, town.
(2) Distance and direction from city or town, road, intersection, etc.
(8) From building (story), yard, etc.
Map coordinates (if feasible) showing latitude and longitude.
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(1) Type aircraft, speed, altitude, direction of flight.
(2) Distance and direction from city, town or known landmark.
(8) Clock position of object from observer’s aircraft.
(4) Latitude and longitude.
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.)
8. Distance of object from observer.
a. Laterally or horizontally.
b. Angle of elevation from horizon.
c. Altitude.
Time in sight.
Appearance of object.
a. Color.
b. Shape. (Sketch if possible)
Apparent construction. (Of what material or substance)
Size.
(1) Estimated size.
(2) Size as it appeared from observer’s view. (Compared to known object)
Direction of flight.
Tactics or maneuvers.
Vertical ascent or descent, horizontal, oscillating, fluttering, evasive, aggressive,
erratic, etc.
Evidence of exhaust.
a. Color of smoke.
vb. Length and width.
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' RESTRICTED
c. Odor (if any).
d. Rate of evaporation.
e. Does trail vary with sound? (spurts)
Effect on clouds.
a. Opened path thru clouds.
b. Forced cloud or mists.
c. Reflected on cloud.
d. Showed thru cloud.
Lights.
a. Reflected or attached.
b. Luminous
c. Blinked on and off in relation to speed.
Support
a. Wings.
b. Aerodynamic list of fuselage.
c. Vertical jet.
d. Rotating cylinder or cone.
e. Aerostatic lift (balloon or dirigible).
Propulsion.
Propeller or jet.
Rotor.
Aerodynamic vanes (flapping or oscillating) (Katz Mayer effect).
Visible exhaust or jet openings.
Control and stability.
a. Fins
b. Stabilizers (horizontal or vertical).
(1) sSize.
(2) Shape.
(8) Location.
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Air ducts.
a. Slots.
b. Duct openings.
Speed - M.P.H.
Sound.
a. Continuous whine or buzz.
b. Roar, whistle, whoosh.
c. Intermittent.
Manner of disappearance.
a. Explode.
(1) Possibility of fragments.
(2) Other physical evidence.
Faded from view.
Disappeared behind obstacle.
Relative to the Observer
Name of observer.
Address.
Occupation.
Place of business.
a. Employer or employee.
Pertinent hobbies.
a. Is observer amateur astronomer, pilot, engineer, etc.
b. Length of time engaged in hobby (experience).
Ability to determine:
a. Color,
b. Speed of moving objects.
c. Size at distance.
5 Reliability of observer.
a. Sources.
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@ 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 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 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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® restricten @
3. 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.
5. I 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.
8. 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, i.e., (any projections or extentions that might presum-
ably be construed as such).
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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s
[) 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 1 - GENERAL
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 256 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.
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: MCIAXO-3.”
RESTRICTED 9-4892,
AF
RESTRICTED
(2) Supplementary written reports, prepared on AF Form 112, will be forwarded to the
Director of Intelligence, Headquarters United States Air Force.
(8) Commanding General, Air Materiel Command is authorized direct contact with major
Alr Commands (overseas) and organizations under their control in connection with the
development of information on this subject.
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) Coplies of such reports may be supplied the Command Headquarters of the installation
concerned.
(8) 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.
Non-Air Force Agencies
(1) Addressees other 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
Date of sighting.
Time of sighting (zonal by 24 hr. clock).
Where sighted (observer’s position):
a. Ground
(1) City, town.
(2) Distance and direction from city or town, road, intersection, ete.
(8) From building (story), yard, etc.
(4) Map coordinates (if feasible) showing latitude and longitude.
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RESTRICTED
Type alrcraft, 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.
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.
Time in sight.
Appearance of object.
a, Color.
b. Shape. (Sketch if possible)
Apparent construction. (Of what material or substance)
Size.
(1) Estimated size.
(2) Size as it appeared from observer’s view. (Compared to known object)
Direction of flight.
Tactics or maneuvers.
Vertical ascent or descent, horizontal, oscillating, fluttering, evasive, aggressive, erratic, etc.
Evidence of exhaust.
a, Color of smoke.
vb. Length and width.
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RESTRICTED
c¢. Odor (if any).
d. Rate of evaporation.
e. Does trail vary with sound? (spurts)
Effect on clouds.
a. Opened path thru clouds.
b. Forced cloud or mists.
c. Reflected on cloud.
d. Showed thru cloud.
Lights.
a. Reflected or attached.
b. Luminous
c. Blinked on and off in relation to speed.
Support
Wings.
Aerodynamic list of fuselage.
Vertical jet.
Rotating cylinder or cone.
e. Aerostatic lift (balloon or dirigible).
Propulsion.
Propeller or jet.
Rotor.
Aerodynamic vanes (flapping or oscillating) (Katz Mayer effect).
Visible exhaust or jet openings.
Control and stability.
a, Fins
b. Stabilizers (horizontal or vertical).
(1) size.
(2) Shape.
(3) Location.
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RESTRICTED
Alr ducts.
a. Slots.
b. Duct openings.
Speed - M.P.H.
Sound.
a. Continuous whine or buzz.
b. Roar, whistle, whoosh.
c. Intermittent.
Manner of disappearance.
a. Explode.
(1) Possibility of fragments.
(2) Other physical evidence.
Faded from view.
Disappeared behind obstacle.
Relative to the Observer
Name of observer.
Address.
Occupation.
Place of business.
a. Employer or employee.
Pertinent hobbies.
a. Is observer amateur astronomer, pilot, engineer, etc.
b. Length of time engaged in hobby (experience).
Ability to determine:
a. Color.
b. Speed of moving objects.
c. Size at distance.
Reliability of observer.
a. Sources.
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RESTRICTED
Neighbors.
Police Dept.
FBI records.
Employer.
8. Notes relative to observer on:
a. Sightings in general.
b. How attention was drawn to object(s).
(1) Sound.
(2) Motion.
(8) Glint of light.
c. Degree of fatigue and duration of flight at time of sighting in cases where observer is
alrborne.
9. Witnesses.
a. Addressees.
b. Occupation,
c. Reliability.
Comments of interrogator regarding the intelligence and character of person interrogated.
Relative to Radar Sightings
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
Teletype sequences of local weather conditions.
Winds aloft report.
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RESTRICTED
3. 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.
5, If object contacted earth, obtaln 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 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, i.e., (any projections or extentions that might presum-
ably be construed as such).
C. P. CABELL
Major General, USAF
Director of Intelligence, Office of
Deputy Chief of Staff, Operations
DISTRIBUTION:
Commanding Generals, Major Air Commands,
Z1 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
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 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 after sightings.
(2) Supplementary reports should be forwarded as available by the most expeditious means
consistent with the importance of the information reported.
Major Air Commands (Overseas) and Alr Attaches
(1) Initial and supplementary cabled reports will be transmitted to the Director of Intelli-
gence, Headquarters United Statecs Air Force. Cables will contain the phase, ‘““Pass to
COMGENAMC WRIGHT-PATTERSON AFB, DAYTON, OHIO, ATTN: MCIAXO-3.”
RESTRICTED 9-4892,
AF
RESTRICTED
(2) Supplementary written reports, prepared on AF Form 112, will be forwarded to the
Director of Intelligence, Headquarters United States Air Force.
(8) 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.
Major Air Commands (ZI)
(1) Reports will be forwarded direct to the Commanding General, Air Materiel
Command,
Wright-Patterson Air Force Base, Dayton, Ohlo, 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.
(8) 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.
Non-Air Force Agencies
(1) Addressees other 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
Date of sighting.
Time of sighting (zonal by 24 hr. clock).
Where sighted (observer’s position):
a. Ground
(1) City, town.
(2) Distance and direction from city or town, road, intersection, etc.
From building (story), yard, etc.
Map coordinates (if feasible) showing latitude and longitude.
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RESTRICTED
Air
(1) Type alircraft, 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.
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.
Time in sight.
Appearance of object.
a. Color.
b. Shape. (Sketch if possible)
Apparent construction. (Of what material or substance)
Size.
(1) Estimated size.
(2) Size as it appeared from observer’s view. (Compared to known object)
Direction of flight.
Tactics or maneuvers.
Vertical ascent or descent, horizontal, oscillating, fluttering, evasive, aggressive, erratic, etc.
Evidence of exhaust.
a., Color of smoke.
vb. Length and width.
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RESTRICTED
¢, Odor (if any).
d. Rate of evaporation.
e. Does trail vary with sound? (spurts)
Effect on clouds.
a. Opened path thru clouds.
b. Forced cloud or mists,
c. Reflected on cloud.
d. Showed thru cloud.
Lights.
a. Reflected or attached.
b. Luminous
c. Blinked on and off in relation to speed.
Support
Wings.
Aerodynamic list of fuselage.
Vertical jet.
Rotating cylinder or cone.
e. Aerostatic lift (balloon or dirigible).
Propulsion.
a. Propeller or jet.
b. Rotor.
c. Aerodynamic vanes (flapping or oscillating) (Katz Mayer effect).
d. Visible exhaust or jet openings.
Control and stability.
a. Fins
b. Stabilizers (horizontal or vertical).
(1) Size.
(2) Shape.
(8) Location.
RESTRICTED
RESTRICTED
Ailr ducts.
a, Slots.
b. Duct openings.
Speed - M.P.H.
Sound.
a. Continuous whine or buzz.
b. Roar, whistle, whoosh,
c. Intermittent.
Manner of disappearance.
a. Explode.
(1) Possibility of fragments.
(2) Other physical evidence.
Faded from view.
Disappeared behind obstacle.
Relative to the Observer
Name of observer.
Address.
Occupation.
Place of business.
a. Employer or employee.
Pertinent hobbies.
a. Is observer amateur astronomer, pilot, engineer, ete.
b. Length of time engaged in hobby (experience).
Ability to determine:
a. Color,
b. Speed of moving objects.
c. Size at distance.
Reliability of observer.
a. Sources.
RESTRICTED
RESTRICTED
Neighbors.
Police Dept.
FBI records.
Employer.
8. Notes relative to observer on:
a. Sightings in general.
b. How attention was drawn to object(s).
(1) Sound.
(2) Motion.
(8) Glint of light.
¢. Degree of fatigue and duration of flight at time of sighting in cases where observer is
alrborne.
9. Witnesses.
a, Addressees.
b. Occupation.
c. Reliability.
Comments of interrogator regarding the intelligence and character of person interrogated.
Relative to Radar Sightings
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
Teletype sequences of local weather conditions.
Winds aloft report.
RESTRICTED
RESTRICTED
3. 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 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, i.e., (any projections or extentions that might presum-
ably be construed as such).
C. P. CABELL
Major General, USAF
Director of Intelligence, Office of
Deputy Chief of Staff, Operations
DISTRIBUTION:
Commanding Generals, Major Air Commands,
Z1 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
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 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 4256.1, 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.
Major Air Commands (Overseas) and Alr Attaches
(1) Initial and supplementary cabled reports will be transmitted to the Director of Intelli-
gence, Headquarters United States Alr Force. Cables will contain the phase, ‘‘Pass to
COMGENAMC WRIGHT-PATTERSON AFB, DAYTON, OHIO, ATTN: MCIAXO-3."”
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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.
Major Air Commands (ZI)
(1) Reports will be forwarded direct to the Commanding General, Air Materiel Command,
Wright-Patterson Air Force Base, Dayton, Ohlo, 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.
(8) 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,
(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.
Non-Air Force Agencies
(1) Addressees other 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
1y 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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(1) Type aircraft, speed, altitude, direction of flight.
(2) Distance and direction from city, town or known landmark.
(8) Clock position of object from observer’s aircraft.
(4) Latitude and longitude.
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.
Time in sight.
Appearance of object.
a. Color.
Shape. (Sketch if possible)
Apparent construction. (Of what material or substance)
Size.
(1) Estimated size.
(2) Size as it appeared from observer’s view. (Compared to known object)
Direction of flight.
Tactics or maneuvers.
Vertical ascent or descent, horizontal, oscillating, fluttering, evasive, aggressive, erratic, etc.
Evidence of exhaust.
a. Color of smoke.
vb. Length and width.
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¢, Odor (if any).
d. Rate of evaporation.
e. Does trail vary with sound? (spurts)
Effect on clouds.
Opened path thru clouds.
Forced cloud or mists.
Reflected on cloud.
Showed thru cloud.
Lights.
a. Reflected or attached.
b. Luminous
c. Blinked on and off in relation to speed.
Support
Wings.
Aerodynamic list of fuselage.
Vertical jet.
Rotating cylinder or cone.
e. Aerostatic lift (balloon or dirigible).
Propulsion.
a. Propeller or jet.
b. Rotor,
c. Aerodynamic vanes (flapping or oscillating) (Katz Mayer effect).
d. Visible exhaust or jet openings.
Control and stability.
a. Fins
b. Stabilizers (horizontal or vertical).
Size.
Shape.
Location.
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Air ducts.
a. Slots.
b. Duct openings.
Speed - M.P.H.
Sound.
a. Continuous whine or buzz.
b. Roar, whistle, whoosh.
c. Intermittent.
Manner of disappearance.
a. Explode.
(1) Possibility of fragments.
(2) Other physical evidence.
Faded from view.
Disappeared behind obstacle.
Relative to the Observer
Name of observer.
Address.
Occupation.
Place of business.
a. Employer or employee.
Pertinent hobbies.
a. Is observer amateur astronomer, pilot, engineer, etc.
b. Length of time engaged in hobby (experience).
Ability to determine:
a. Color.
b. Speed of moving objects.
c. Size at distance.
Reliability of observer.
a. Sources.
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Neighbors.
Police Dept.
FBI records.
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.
¢. 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.
Comments of interrogator regarding the intelligence and character of person interrogated.
Relative to Radar Sightings
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°), ete. 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?
¢. 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
Teletype sequences of local weather conditions.
Winds aloft report.
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3. Local flight schedules of commercial, private and military aircraft flying in vicinity at the
time. (Check Canadlian 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. I 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. 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, i.e., (any projections or extentions that might presum-
ably be construed as such).
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
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