Fighter Combat - Tactics and Maneuvering

154 ONE-VERSUS-ONE MANEUVERING, DISSIMILAR AIRCRAFT
favorite tactics was to make a high-speed diving attack on his victim, then
pull up vertically, perform a rudder reversal, and dive back down for
another attack, and so on, until the target was destroyed. This tactic so
confounded his Allied opponents that they dubbed it the "Immelmann
Turn" and were convinced it defied the laws of aerodynamics. Once it was
figured out, the technique was widely copied by both sides. Today there is a
precision aerobatic maneuver known as an "Immelmann," but it varies
considerably from the original. The modern Immelmann begins with the
first half of a loop to the inverted position, followed by a roll to the upright
attitude at the top.
The Immelmann Turn was very successful. . . . But later, when more powerful
engines became available, it was a dangerous move, for the lower pilot
could climb after the Fokker and attack when it hung almost motionless in
the vertical position, not under full control, and presenting an easy shot.
Air Vice-Marshal J. E. "Johnnie" Johnson, RAF
Passing directly over the bogey and then pulling down toward its six
o'clock almost ensures that the opponent will lose sight of the energy
fighter temporarily. Faced with these tactics, the bogey pilot essentially
has only two options. He can begin to turn almost immediately in a level or
slightly oblique plane, attempting to regain sight and to hamper the attacker's
impending gun shot, or he can continue an unloaded diving acceleration.
In the first case his guns defense is not likely to be successful
because of low G available at his slow airspeed. In the second option he
almost surely will not regain sight of the attacker and will be forced to
guess when to perform his guns break. If he guesses correctly the guns
defense should be more effective at the resulting higher airspeed. An
incorrect guess should terminate the engagement.
In the event that the energy fighter pilot misses the shot at time "4," a
vertical overshoot is probable. At min-range the attacker can unload or roll
away from the target aircraft (quarter roll away) and continue to dive for
separation. Generally his speed advantage in the dive will carry him
beyond guns range before the opponent can reverse and threaten a shot.
This separation and speed advantage then can be used to exit the fight or to
return for another head-on pass. If the vertical overshoot is not great and
the energy fighter has attained at least vertical-maneuvering speed at the
overshoot, the pilot may choose to pull immediately up into another
vertical pitch-back and repeat his overhead attack. However, if the overshoot
carries the attacker substantially below the bogey's altitude (i.e.,
approaching the equivalent of one attacker turn radius), the energy fighter
pilot first should climb back up near the bogey's altitude before beginning a
second vertical maneuver. Otherwise the altitude advantage on the top of
the second pitch-back may be less than required, resulting in an even
greater overshoot on the next pass.
Some modification may be required in these tactics if the energy fighter
is subject to restrictions against prolonged zero or negative G. The fuel or
oil systems of many power plants may cause temporary engine stoppage or
even permanent damage when engines are subjected to these operating