I recently watched Behind Enemy Lines on television the other day. My favorite part of the film is near the beginning, when the US fighter plane doing a recon sweep gets chased by two surface-to-air missiles. This raised a couple of questions about the nature of the missiles, and the various planes they are trying to chase down and destroy.
1.) Obviously a surface-to-air missile, or air-to-air missile will have to be capable of moving faster than its target, so it can chase it down if the target aircraft is moving away from the missile. However, what is the typical difference in speeds? I have heard many of these missiles are capable of flying at Mach 3 or greater. Most modern fighter jets I have heard about can go somwhere in the Mach 2 range…this means at the very best, the missile is still overtaking the target by the equivalent of the speed of sound :eek: That seems like a window of a fraction of a second to do anything to evade the missile! Are there planes out there today that can outrun these missiles? Really, all the plane would need to do is go as fast as the chasing missile, and wait until the missile ran out of fuel.
2.) Is it possible for a fighter dodging a missile to shoot the missile down? Some of these missiles are not terribly maneuverable. I know that in Vietnam, many pilots opted to do a head-on pass against emerging SAMS- they would fly toward the missile, then bank at the last second, which would result in the SAM flying past the plane at great speed and winding up too far away (probably) to turn around and give chase. However, much has improved since then. Could a particularly maneuverable plane position itself to destroy a SAM or AAM with missiles of its own, or guns? If a plane had a missile chasing it, could a wingman assist by trying to knock out the missile? What would happen if a vulnerable plane, such as an AWAC, was being chased by an exceptionally long-ranged missile- would the AWAC’s fighter screen be able to knock it out? I know that the Phoenix missile was originally designed for shooting down both bombers and cruise missiles, but are there weapons that can destroy the smaller missiles as well? Would guns be effective?
3.) Just how maneuverable are these missiles? Being smaller than most targets they are chasing, I imagine that they would almost always be more maneuverable. But there are some planes out there that seem exceptionally acrobatic and maneuverable, like the Russian Super-Flanker fighters.
In many cases the missile runs out of fuel immediately after it is launched. This is probably the case for most solid-propellant, short-range missiles such as Sidewinder-type air-to-air missiles and shoulder-launched SAMs. The missile quickly accelerates to its maximum speed, then spends the rest of its flight decelerating. The missile’s maximum speed is likely to be far greater than the speed of its target, so it is still likely to reach its target before it falls to the ground. (Most missiles of this type have a range less than ten miles, and the range varies greatly depending on the position of the target.)
Evading missiles aerobatically looks great on movie screens, but I doubt a real pilot would try to dodge or outrun an incoming missile. It may work to some extent, but I would think countermeasures that lead the missile away from its target would be more effective. A hot flare can mislead infrared-seeking missiles, electronic or physical countermeasures can trick radar-guided missiles, and ground- or air-based radars used to guide some missiles can be jammed. Some movies do show this, but it’s a lot less dramatic than showing a pilot evade a missile or asking his wingman to shoot it down. AFAIK aircraft cannot shoot down incoming anti-aircraft missiles, though some may have the means to intercept cruise missiles, which are much slower. Surface ships have high-speed SAMs and radar-tracking high-rate-of-fire cannon to destroy incoming anti-ship missiles. (A surface ship shooting down a missile a second or two before it hits must be very dramatic, but I’m not sure if I’ve seen that in a movie.)
I believe that when you have a missile fired at you, you pretty much have one shot at avoiding it. You drop your flares and or chaff (to confuse the missile) and turn tight in towards it so as to give the missile the tightest turn for it to be able to get you, they aren’t particularly manoeuvreable so probably (hopefully) won’t make the turn.
If it’s air to air then outrunning probably isn’t an option as you would have been travelling at dog fighting speeds rather than fast cruise speeds. Also, the vast majority of military aircraft that are capable of speeds over Mach 1, aren’t able to sustain those speeds without using up serious fuel.
The airplane has bigger wings, so it can take tighter turns. So an airplane can quite easily avoid one missile, but things get really tough if it is being chased by two missiles.