indranilroy wrote:An aircraft generally can't pull many Gs while travelling supersonic. On the other hand, A2A missiles have airframes specifically designed for this. Most modern missiles can pull in excess of 30 Gs. Coupled with TVC, they can keep the aircraft within their FOV, even when they are skidding into the turn.
checking my scribbled notes, if the aircraft is pulling x g's, the missile has to pull the same G's X difference in speed squared. missiles can't throttle (Meteor supposedly can to a limited extent), so higher speed, higher G's, higher turn radius. which is why the aircraft can go at much lower g's but the missile by default has to put in extra effort.
Actually, if you want to get out of the FOV, you should gun for the speed at which you can change your angular velocity at the fastest rate wrt to the missile. That speed is subsonic for all planes that I know of. There are two contradictory effects in play here. 1. Lift (+/- gravity) provides the centripetal force required for the turn, which increases non-linearly with speed. 2. For a given centripetal force, angular velocity falls proportionally to the increase in linear peed. Of course drag and power have rolls to play too, but let's not get there today.
the issue is whether you know where the missile is targeting you and whether you are in its FOV or not. so what you'll do is try and maximize several factors at once. try to break lock (assuming you are in the FOV of the radar and or missile) and maximize distance between yourself and the missile and attempt to waste missiles energy (since most of these use Proportional navigation and "lead" the target, so rapid changes in direction will help) and also put excess strain on the seeker (for RF, receding targets even without ground clutter have acquisition ranges at a third of approaching ones; for IR afterburner signatures are higher). while all this going on, soft kill is working too (ECM of whatever kind). so tactics will have to take all these factors into account at the same time.
modern sraams using IIR seekers are another complication. no way to jam them.
imo, given how complex these things can get, i bet IAF (and all AF) have a predetermined set of maneuvers taught for certain criteria and for maximum safety, they will automatically follow these maneuvers given a function of range (1st criteria, since it determines time available) and missile type (2nd- determines soft kill measures - automatic assumption, that BVR/SAM is RF, WVR is IR and also whether speed and airframe heating is avoidable).
in short, subsonic will work, if you are far away and have an early detection (more time to play cat and mouse) OR you got taken by surprise and have to react instantly (instead of waiting for the engine to spool up). not necessary that it will be ineffective. but timing is critical, and that depends on pilot skill. in ODS, Iraqi pilots with limited training repeatedly tried subsonic evasion, and failed due to a variety of factors.
supersonic will be used for maximum safety (take a rapid turn at subsonic speed, tight turns possible, more G's can be piled on) and then go supersonic - either diving towards the ground or after a second change in direction. aim being to break doppler radar lock and also missile lock.
all this possible, if your missiles have already gone active or you are willing to escape rather than stick on and pursue.
taken in combination, these would result in a rapid change in direction, plus speed (adding further energy so as to give more options)
the EF has an interesting pilot friendly solution. maneuvers display on the MFD with verbal cues for the pilot to initiate.