Fighter Combat - Tactics and Maneuvering

24 FIGHTER WEAPONS
The next best thing to denying the attacker any shot at all is to deny him
a good shot. This can be accomplished by complicating the task of any of
the gun subsystems. Looking a little deeper into the requirements for a
good gun shot will clarify the discussion that follows. Figure 1-4 is a
representative guns "envelope," looking down on the target located in the
center, which is heading toward the top of the page. It can be seen that the
effective guns envelope is defined by the min-range boundary (primarily a
function of closure) and the max-range boundary (primarily a function of
gun/ammunition characteristics, dispersion, lethality, gunsight, closure,
apparent target size, and vulnerability). Note that min-range is much
greater in the target's forward hemisphere because of higher closure. Maxrange
is also generally greater in the forward hemisphere for the same
reason. This relates to shorter bullet TOP, smaller dispersion radius, and
greater bullet density on the target. Lethality is also improved in the
forward hemisphere since greater bullet kinetic energy is provided by the
closure. Maximum effective range increases in the target's beam because
of larger apparent target size and better fuzing of the shells (cannon)
resulting from a higher "grazing angle" with the target. Low grazing angles
in the forward and rear quarters may allow shells to bounce off the target
without penetrating or exploding.
As might be expected, within the overall effective envelope of the gun
some areas are better than others. The tracking area is limited on the
min-range side by the attacker's ability to turn fast enough to stop the
target's LOS rate. In the case depicted, the target can be tracked slightly
forward of the beam at long ranges. The forward limit is predicated on
sufficient tracking time between max- and min-range to ensure destruc-
Figure 1-4. Effective Guns Envelope