Project Blue Book Special Report No. 14: Analysis of Reports of Unidentified Aerial Objects

CODE 67 ANGULAR ACCELERATION
(Change in angular velocity) CODE 68 APPEARANCE BEARING
X Variable
Y
0 Zero, V = constant
1 Increasing slowly
2 Decreasing slowly
3 Increasing fast
h Decreasing fast
5 Increasing very fast
6 Decreasing very fast
7
8
9
X
Y
0
1
2
3
h
5
6
7
8
9
i
N
NE
E
SE
S
sw
w
NW
CODE 69 DISAPPEARANCE BEARING CODE 70-71 ELEVATION
WITH RESPECT TO GROUND, DEGREES
X Disappeared suddenly
Y
ON
1 Ne
2 E
3 Se
US
5 SW
6 W
7 NW
8
9
X
Y
0
1
2
3
h
5
6
7
8
9
Initial
Variable
-
0-9
10-19
20-29
30-39
U0-U9
50-59
60-69
70-79
80-89
X
Y
0
1
2
3
U
5
6
7
8
9
Final
Variable
0-9
10-19
20-29
30-39
U0-U9
50-59
60-69
70-79
80-89
CODE 72 OBJECT ORIENTATION
Apparent inclination of principal
axis of object from horizontal CODE 73 MANEUVERS
X Variable
Y
0 +90° to 60°
1 +60° to 30°
2 +30° to 10°
3 +10° to 0°
h 0°
5 0° to -10°
6 -10° to -30°
7 -30° to -60°
8 -60° to -90°
9
X
Y
0
1
2
3
U
5
6
7
8
9
CODE 7U OBSERVER OCCUPATION
Y Civilian, occupation not stated
0 Army, military
1 Navy, military
2 Marine, military
3 Air force, military
h Coast guard, military
5 Merchant marine, military
6 Commercial air, civilian
7 CAA, civilian
8 Government contractor, civilian
9 Civilian, other I
307