Fighter Combat - Tactics and Maneuvering

TACTICAL INTERCEPTS 347
often have the capability to "track" a target in order to gain more detailed
information on its relative position, speed, altitude, etc. Often such radars
are also capable of guiding air-to-air weapons to the target; that is, they
may also serve as guidance radars. Advances in radar and microprocessors
make it feasible now even to identify a target directly through its radar
signature. The return from so-called "millimeter-wave" radars, rather
than displaying only a target blip, may actually depict a recognizable target
shape. This capability is not generally available to current fighters, however,
so other means of identification are employed. Visual identification
is most common, but there are also several electronic identification systems.
Each system has its limitations: VIDs are dependent on visibility
and have relatively short ranges, while EIDs are sometimes unreliable and
are subject to deception and jamming.
This chapter is designed to provide insight into some of the considerations
involved with tactical radar intercepts by describing a few of the
most common intercept tactics. The scope of this discussion is generally
limited to daylight visual conditions. All possible intercept tactics
obviously cannot be included here, but an attempt has been made to
present a representative sample that can furnish options to cover most
tactical situations.
No one can tell another what to do in a future air-to-air fight. ... In this
game, there is a great demand for the individual who can "play by ear."
Major Frederick C. "Boots" Blesse, USAF
Intercept Terminology
Before proceeding with the discussion of specific intercept tactics, it is
necessary to define some terminology. Figure 10-1, which shows a target
and an interceptor on convergent courses, illustrates some frequently used
terms. The solid line between the two aircraft represents the radar line of
sight (LOS). The angle between the LOS and the target's course is known
as the target-aspect angle (TAA), target aspect, or simply "aspect." This
aspect may be computed automatically by a sophisticated tracking radar,
or it may be calculated mentally by the interceptor pilot based on target
bearing (the orientation of the LOS with respect to magnetic north) and
GCI's estimate of the target's magnetic heading. Lateral separation is the
perpendicular distance from the interceptor to the bogey's flight path. This
quantity is usually estimated by the pilot and is a function of target range
and aspect. Lateral separation is important if the interceptor plans to make
a "conversion turn" to the target's rear hemisphere, since allowance must
be made for the interceptor's turn radius. The amount of lateral separation,
or "displacement," required is a function of the interceptor's intended turn
radius and the amount of turn necessary to complete the intercept. This
conversion turn is often described by the number of degrees the interceptor
must turn to parallel the target's course and is called "degrees to go"
(DTG). DTG is determined by calculating the difference between interceptor
heading and the estimated bogey heading.
At given target and interceptor speeds, the interceptor can use heading
changes to control displacement. Assume that if both aircraft continue on
their present courses in this example they will eventually collide. In that