the aircraft has been designed with a clear understanding of the effects of 'stealth' on air combat when both sides present with low-observable aircraft. Obviously, the combatants will be closer when their radar sensors detect the other side, so close in fact that the Infra-Red Scan and Track (IRST) might be the first sensor to detect the presence of an enemy aircraft. The problem is this: the PAK-FA has IRST capability and the F-22A does not. Worse, the extreme agility of the PAK-FA will allow it to dodge the F-22A's AIM-120 missile shots, while the Raptor will likely not be able to out-turn the more advanced Russian (and Chinese) missiles. Surviving F-22As would then be committed to what fighter pilots call a 'knife fight' – close-in dogfights where superior agility wins – and the PAK-FA will out-manoeuvre the F-22A.
Yes the F-22 is vulnerable in WVR - name one fighter that is invulnerable in a 'knife fight'? An F-22 pilot will have to be monumentally stupid to abandon a considerable LO advantage and engage in a dog fight.
IR sensors provide good angular resolution but not range. Radar and lasers offer good range resolution but poor angular resolution. A combination of sensors is always employed in an engagement.
In other words the PAK-FA cannot rely solely on its IRST sensors to track and target an F-22. In addition, the IR signature of a penetrating F-22 is dominated by aerodynamic heating of the skin and not the exhaust; a key design consideration for the F-22 is to limit IR detection to 10 km at a penetration speed of mach 1 from a
lower threat surveillance altitude (adversary is at a lower altitude). The altitude and MACH speed is of crucial importance because the F-22 is designed to blend into the sky when seen by IRST sensor from a lower altitude at MACH 1 or lower speeds. This is rumored to have been achieved by using fuel to cool leading edges and lower wing surface, this explains why the Raptor is easily visible to space based IR sensors but less visible to ground based or lower altitude IR sensors. F-22 is a networked fighter; it will likely acquire target data (including IR) in real time from AWACS and satellites and so IRST sensors are considered unnecessary for current block Raptors.
The Raptor can be beaten by forcing it to compete outside its operational envelope; a 1-v-1 dog fight is an example of the opponent forcing the F-22 to fight by its rules, even in a 1-v-1 dog fight I believe the Raptor will prevail against most adversaries may be 50-50 against the PAK-FA but is the risk of losing an expensive fighter worth the reward of neutralizing just
one enemy combatant? A rhetorical question the answer should be obvious to most, in the real world, air combat is not about proving which plane or pilot is better it is about accomplishing a mission efficiently.
