HUD Air-to-Air Symbology
In the air-to-air mode (Figure 17)
the time to the selected
steerpoint, ground speed, and
bank angle indicators are not
displayed. Because you are
maneuvering in relation to other
aircraft, specific bank angle is
unimportant; pitch bars will still be
displayed and you can use them
as a bank angle reference. The
selected submode is indicated by
LAC or RTGS displayed just
above GUN on the right center of
the PDU. An X over GUN
indicates that the master
armament switch on the
armament control panel is set to
SAFE. The X is removed when
the master armament switch is
set to ARM.
The wingspan setting you entered
sets the diameter of the reticle in
both LAC or RTGS. With the
bogeys wingspan set, the reticle
can be used to estimate range.
Figure 17: AIR-TO-AIR MODE
At 1000 feet, the bogeys wings
fill the inside diameter of the
reticle. The center of the A/A
aiming reticle, the pipper, indicates the computed impact point. Each submode computes the impact point
In LAC the pipper indicates the impact point of the round at 1000 feet, but you need to track the target for
at least 1 second to get a valid aiming solution. Therefore, LAC is used for a mildly maneuvering target.
In RTGS the pipper indicates the instantaneous impact point of the round at 1000 feet. Since it will take 1/
3 of a second for the round to travel 1000 feet, you need to place the pipper ahead of your targets flight
path to account for the rounds time of flight. At 400 KIAS, the bogey travels 222 feet in 1/3 of a second.
So, with 30 degrees angle off, place the pipper about the inner diameter of the reticle ahead of the aircraft.
RTGS is used for a hard-maneuvering target.
The technique for using the HUD is basically a matter of experience. As you maneuver your aircraft, the
reticle will move on the PDU as it compensates for g and yaw. For this reason, the more smoothly you
maneuver your aircraft while tracking, the more accurate the aiming solution. During hard maneuvering,
the reticle may peg to the side of the PDU and begin to flash. At this point the aiming solution is invalid
and you should continue to maneuver to place the bogey on your nose. When the reticle stops flashing,
the aiming solution is accurate.