Originally posted by JFrazier
Anyone care to list the various reasons stated here about why the Raptor couldn't do the Cobra?
*No vortex aerodynamics
*Russian aerodynamics are better
*Stealth gets in the way
*Stable airframe
Anything else?
[edit on 4-9-2006 by JFrazier]
Cobra is all about pitch authority up to and through extreme AoA, lateral stability at extreme AoA, and also engine tolerance to operating in such
conditions, i.e. they don't stall.
You don't need to generate lift at 60 deg AoA to do a cobra, you just need to be able to sustain a pitch rate to 90 degrees+, and then of course
retain the authority to induce a negative pitch rate to get the nose down again.
Anyway, to your specific points:
- Vortices; the f-22 induces its vortices off the forebody (the engine intakes), while not providing the same strength as an equivalent LERX, it does
the job.
- The Flanker/Fulcrum series' have pukka LERXs, so it can be expected they produce a more intense vortex, hence more lift at extreme AoA.
- Stealth in the way; Its certainly another design factor that requires compromise, for instance the F-22 was not allowed to use ventral fins, even
though the stability and control crowd wanted it, the low-observable people said no-no.
- I'm pretty sure the F-22 is an unstable airframe (in pitch).