reply to post by BlueRaja
Thrust vectoring is useful for two things - at low air-speeds, and high angles of attack.
Maneuvering at low air speeds is nice.... but most useful for airshows and impressing people who don't understand that a "dogfight" (merger) takes
place at distances of several miles.
Furthermore, many people seem to think that a plane can somehow "scoot around" a missile. It doesn't work that way. A missile is a guided
ballistic claymore mine. It zings off at supersonic speeds on an interception course with the aircraft. It does not "chase" the target - it merely
makes adjustments so it will run into it. However, actually hitting something the size of a semi-truck in three dimensional space over several miles
is rather difficult. To improve the odds of a kill, the warhead of a missile is designed to fragment, generating shrapnel that will shred the
control/lifting surfaces, foul the engine, and do to planes what bird-shot does to birds.
Thrust-vectoring does nothing to give any appreciable advantage against any missile. It is useful for getting your nose pointed in the right
direction - but modern combat avionics allow a missile lock to be obtained from wingmen and other networked sensor devices - making the "all knowing
radar" in many games not too far off from what modern combat systems can achieve. It's nice to have - but I'd rather have an LO exhaust manifold
as opposed to a TVC manifold. In real combat - you or the target is dead before you close to ranges where TVC is effective.
As for angles of attack - research into airframe and surface design has lead to a number of ways to improve the performance of control and lifting
surfaces at high angles of attack. One project (though one conducted in Russia) involved the concept of a 'moving' upper surface - much like a
treadmill. Tests showed that surfaces could remain departure-resistant (resist flow separation) well into 105 degrees AoA. Other (perhaps more
practical) methods utilize porous materials and manipulating the boundary layer to delay flow separation.
Ultimately - improving the performance of lifting and control surfaces through high angles of attack by means of delaying flow separation (a
departure/stall) and other airframe design considerations is vastly superior in overall benefit than anything that can be provided by thrust
vectoring. (lift can be increased on a given surface and maintained through higher angles of attack - which is far more beneficial to a performance
(military) aircraft than thrust-vectoring).
So, it's not anything that's really necessary on a combat aircraft. It would actually just add to complexity, cost, and other things that countries
do not want. Even the lightest TVC implementations are quite heavy for an aircraft; ALL of them expensive; and they are just more things to break or
be improperly maintained/calibrated (would be pretty interesting if the ground crew accidentally reversed the controls, somehow.... - perhaps
impractical, but certainly the type of concern that would be raised by government seats).
It's impressive at air-shows, when you want aircraft to be moving slow enough to be seen - but, otherwise, that's about the extent of its
usefulness. The military application of TVC is rather null in today's combat (and in the foreseeable future) scenarios.
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