Fighter Combat - Tactics and Maneuvering

8 FIGHTER WEAPONS
angle is also dependent on the geometry of the firing situation because of
the influence of this factor on target crossing speed and TOP. This geometry
can be described as "target-aspect angle" (TAA), which is denned as the
angle between the target's velocity vector (flight path) and the LOS betwen
the target and shooter. When the target is moving directly toward the
shooter, TAA is zero. The shooter would have a 180° TAA when he is
situated directly behind the target, and a 90° TAA on the target's beam (i.e.,
"abeam" the target). As TAA varies, so does target crossing speed, changing
the lead angle required.
I had no system of shooting as such. It is definitely more in the feeling side of
things that these skills develop. I was at the front five and a half years, and
you just get a feeling for the right amount of lead.
Lt. General Guenther Rail, GAP
Third Leading Luftwaffe Ace, WW-II
275 Victories
To this point only nonmaneuvering targets (i.e., those traveling in a
straight line at constant speed) have been discussed. To gain an appreciation
of the effects of target maneuvering on lead angle, assume that the
shooter is directly behind the target at the moment of firing, but before the
bullet TOF the target begins a turn to left or right. If the shooter applied no
lead angle (because target crossing speed was zero at the time of firing), the
bullet might pass behind the target. The target's lateral acceleration (radial
G) has generated an average crossing velocity that requires a lead correction.
The amount of this lead correction is very sensitive to target G near
nose or tail TAAs, but it is less dependent on target maneuver (and more
dependent on target speed) near beam aspects when the target turns directly
toward or away from the shooter.
Target movement and maneuver also affect range. If TOF, gravity drop,
lead angle, etc., are calculated based on target range at the time of firing
(position "1" in Figure 1-1), any movement or maneuver during projectile
TOF could change the range, invalidating all calculations and causing a
miss.
Figure 1-1. Gun-Firing Geometry