Fighter Combat - Tactics and Maneuvering

ONE-VERSUS-ONE MANEUVERING, DISSIMILAR AIRCRAFT 151
supersonic fighter engages a bogey that is limited to subsonic speeds. Just
how much excess speed is required can be estimated using an altitude-
Mach (H-M) diagram or Equation 3 in the Appendix before the engagement.
Assuming an engagement altitude, the bogey's maximum attainable
energy level can be located on the chart. Adding the desired energy
(altitude) advantage to the bogey's energy level determines the approximate
energy level required of the high-T/W fighter. The speed at which
this desired energy level intersects the engagement altitude represents the
necessary airspeed of the energy fighter.
The speed advantage necessary to provide a given zoom-altitude advantage
is highly dependent on the bogey's airspeed. For example, a 2,000-ft
zoom advantage over a bogey traveling at 100 knots true airspeed (KTAS)
would require the energy fighter to have about 130 knots of excess airspeed
(230 KTAS total). But with the bogey at 500 KTAS, the energy fighter
would need about 540 KTAS (only a 40-knot advantage). Although faster
bogeys require less speed advantage for the energy fighter to attain a given
zoom-altitude margin, this phenomenon is offset to a large degree because
faster fighters generally need more altitude margin. The figures given here
are only gross estimates, since they do not consider possible energy
changes during the zoom maneuver.
Assuming this energy advantage can be attained at the first pass, the
pilot of the high-T/W fighter may choose to zoom immediately, as shown
in Figure 4-5. The major difference between this scenario and that of Figure
4-4 comes from the great energy advantage of the high-T/W fighter in this
case, which enables the energy fighter to remain well above its opponent,
and facilitates its maneuvering in the vertical plane.
In this scenario the energy fighter has a substantial speed advantage
approaching the pass (time "1") as well as slightly greater altitude.
Together this speed and altitude advantage form the high-T/W fighter's
desired energy margin. The purpose of the height advantage in this case is
not only to provide extra energy margin, but also to induce the bogey pilot
into a sharply nose-high maneuver. Allowing some vertical separation
(i.e., passing almost directly over the bogey) gives the bogey room for a lead
turn, but the pilot must turn almost purely in the vertical to take advantage
of it. Too much separation here may provide the low-wing-loaded
opponent a reasonable snapshot at the pass, while too little vertical advantage
offers him little incentive to zoom. An altitude advantage at the pass
equal to about one-quarter of the bogey's best turn radius is usually a good
compromise.
In Figure 4-5 the angles fighter begins a near-vertical lead turn at time
"1," while the energy fighter continues straight ahead for a few seconds.
Here the pilot of the energy fighter must assess whether the bogey pilot has
timed his pull-up properly to gain lead for a gun snapshot at the pass. If so, a
quick out-of-plane (level) jink is in order to spoil the shot before he starts a
pull-up of his own. This slight delay in the energy fighter's zoom also helps
the pilot keep sight of the bogey underneath. The energy fighter should
begin its pull-up, at sustained-G levels, as the bogey begins to approach
effective guns range. Turning up and away from the bogey at this point