Fighter Combat

154 ONE-VERSUS-ONE MANEUVERING, DISSIMILAR AIRCRAFTfavorite tactics was to make a high-speed diving attack on his victim, thenpull up vertically, perform a rudder reversal, and dive back down foranother attack, and so on, until the target was destroyed. This tactic soconfounded his Allied opponents that they dubbed it the "ImmelmannTurn" and were convinced it defied the laws of aerodynamics. Once it wasfigured out, the technique was widely copied by both sides. Today there is aprecision aerobatic maneuver known as an "Immelmann," but it variesconsiderably from the original. The modern Immelmann begins with thefirst half of a loop to the inverted position, followed by a roll to the uprightattitude at the top.The Immelmann Turn was very successful. . . . But later, when more powerfulengines became available, it was a dangerous move, for the lower pilotcould climb after the Fokker and attack when it hung almost motionless inthe vertical position, not under full control, and presenting an easy shot.Air Vice-Marshal J. E. "Johnnie" Johnson, RAFPassing directly over the bogey and then pulling down toward its sixo'clock almost ensures that the opponent will lose sight of the energyfighter temporarily. Faced with these tactics, the bogey pilot essentiallyhas only two options. He can begin to turn almost immediately in a level orslightly oblique plane, attempting to regain sight and to hamper the attacker'simpending gun shot, or he can continue an unloaded diving acceleration.In the first case his guns defense is not likely to be successfulbecause of low G available at his slow airspeed. In the second option healmost surely will not regain sight of the attacker and will be forced toguess when to perform his guns break. If he guesses correctly the gunsdefense should be more effective at the resulting higher airspeed. Anincorrect guess should terminate the engagement.In the event that the energy fighter pilot misses the shot at time "4," avertical overshoot is probable. At min-range the attacker can unload or rollaway from the target aircraft (quarter roll away) and continue to dive forseparation. Generally his speed advantage in the dive will carry himbeyond 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 toreturn for another head-on pass. If the vertical overshoot is not great andthe energy fighter has attained at least vertical-maneuvering speed at theovershoot, the pilot may choose to pull immediately up into anothervertical pitch-back and repeat his overhead attack. However, if the overshootcarries the attacker substantially below the bogey's altitude (i.e.,approaching the equivalent of one attacker turn radius), the energy fighterpilot first should climb back up near the bogey's altitude before beginning asecond vertical maneuver. Otherwise the altitude advantage on the top ofthe second pitch-back may be less than required, resulting in an evengreater overshoot on the next pass.Some modification may be required in these tactics if the energy fighteris subject to restrictions against prolonged zero or negative G. The fuel oroil systems of many power plants may cause temporary engine stoppage oreven permanent damage when engines are subjected to these operating