TM 55-6930-212-10
8-97. The following EW threat types are also shown at the bottom of threat array page 025:
ZSU-23-4
SA-4
SA-6
SA-8
FLAPWHEEL
8-98. The APR-39 indicator displays up to three threats simultaneously. In the out-the-window visual scene, a maximum
of three threats can be shown at any given time, provided that the ownship is close enough to see all three.
8-99. The relationship between visual threats (out-the-window) and the hostile ground fire switch is that when the switch
is depressed, muzzle flash occurs at each of the visual threats. In practice, the distances between visual threats are
such that probably only one threat muzzle flash will be seen at any given time.
8-100. KILL CONDITIONS FOR ANTI-AIRCRAFT ARTILLERY SITES.
8-101. The following are kill conditions from anti-aircraft artillery (AAA):
ZSU-23-4 - A kill from this threat occurs 4 seconds after going into track
Flapwheel - A kill occurs 10 seconds after going into track.
8-102. KILL CONDITIONS FOR SURFACE-TO-AIR MISSILES.
8-103. A kill from one of these surface-to-air missile (SAM) threats occurs as a function of that threat's range to the
aircraft (at the time each threat time in track is exceeded) and that threat's average velocity. The track time for each
missile is shown in table 8-12. Average velocities and an example are shown below:
Average velocities
SA-4 = Mach 1.25 = 413.75 m/sec
SA-6 = Mach 1.4 = 463.4 m/sec
SA-8 = Mach 1.0 = 331.0 m/sec
Example:
a. At a range of 10 km, the SA-4 would kill the A/C in 100000M÷413.75 m/sec = 24 seconds after the track time
of 10 seconds is exceeded or 34 seconds after going into track.
b. At the same range, a kill from the SA-6 would occur in 10000M÷463.4 m/sec = 21.58 seconds after the track
time is exceeded, or 28.58 seconds after going into track.
c. The SA-8, at the same range, would kill the A/C in 10000M÷331 m/sec = 30.21 seconds after track time is
exceeded, or 37.21 seconds after going into track.
8-92
