Fighter Combat

FIGHTER WEAPONS 5 1Besides the guidance problems already discussed, very low altitudeemployment of AAMs offers other difficulties. Most guidance and controlsystems cause the missile to oscillate some distance around the intendedtrajectory. At very low altitudes one of these corrections may result inground impact. Fuzing can also be a concern, especially with active fuzes,since the surface may be mistaken for the target by the fuze, causingpremature detonation. Ground clutter may have the same effect withDoppler-rate fuzes.Extremely high altitudes also can cause problems for missiles, as thethin air reduces the maneuvering capability of aerodynamic controls andresults in sloppy guidance.The advent of AAMs having capability against targets with forwardaspect, particularly semi-active AAMs, has increased the importance of aperformance parameter known as "relative range." A missile fired at itsmaximum relative range results in target impact at the greatest distancefrom the launching aircraft. The shooter-to-target range at impact is oftencalled "F-pole" or stand-off distance. When two missile-equipped fightersapproach nearly head-on, the one with the greater F-pole generally has theadvantage, since its missile would arrive on target first. In the case ofsemi-active missiles, which require target illumination by the launchingaircraft, this also terminates any threat from the enemy's missile still inflight. Maximum stand-off distance occurs when the missile decelerates tothe speed of the launching aircraft. After this point the shooter wouldbegin to close on his own missile, decreasing the range at target impact.Maximum relative range is generally somewhat less than the ultimateaerodynamic range, but a missile launched at this point will arrive ontarget first. So, depending on average missile speed, the aircraft firing firstis not necessarily the winner of such a game of "chicken." However, amissile in the air has an uncanny ability to attract the attention of the pilotin the target aircraft, often causing him to forget all about launching hisown weapon. Because of this psychological factor missiles are sometimes"fired for effect" even when the shooter knows there is little chance forsuccess. The target's defensive reaction may place the shooter in a muchmore favorable position. In some cases it may be advantageous to fire onemissile at maximum aerodynamic range, or even beyond, for effect, andfollow it with another at maximum relative range. This is often possiblewith radar missiles, but a second heat seeker may conceivably guide on thetailpipe of the first one, limiting the usefulness of this tactic with heatseekingmissiles. Missiles of two different types are often fired together,since target defensive countermeasures employed against one may beineffective against the other.Increased stand-off distance is also valuable in that it may allow assessmentof the results of the first missile and, if necessary, permit the firing ofanother before minimum range is reached. Under almost any imaginablecircumstances, missiles with launch-and-leave capability are preferable tosemi-active types with about equal range, since the former do not restrictthe shooter's maneuver capability after launch.Maximum F-pole normally can be increased by firing the missile athigher aircraft speed (which in turn increases the missile's velocity), and