Forum: General F-22A Raptor forum

Last edited by mil_hobbyist on Jun 22, 2010 - 07:39 AM; edited 1 time in total

This question is motivated by the "F-35 with thrust vectoring thread." If the F-22 did not have thrust vectoring, how would it perform relative to current fighters without thrust vectoring (e.g F-15, F-16, Sukhois)?

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The reason the F-22 has TV is to reduce drag during supercruise and to maneuver more effectively at supersonic speeds. Since the opposing fighters probably won't see the F-22 anyway it's moot.

shingen wrote:

The reason the F-22 has TV is to reduce drag during supercruise and to maneuver more effectively at supersonic speeds. Since the opposing fighters probably won't see the F-22 anyway it's moot.

I agree it would have little impact on the effectiveness of the F-22 in combat.

mil_hobbyist wrote:

This question is motivated by the "F-35 with thrust vectoring thread." If the F-22 did not have thrust vectoring, how would it perform relative to current fighters without thrust vectoring (e.g F-15, F-16, Sukhois)?

The effect would be negligible. It'd have less post stall and high altitude agility, and a bit more drag while supercruising, but its pre stall performance would be relatively unchanged.

wrightwing wrote:

The effect would be negligible. It'd have less post stall and high altitude agility, and a bit more drag while supercruising, but its pre stall performance would be relatively unchanged.

I would guess that pilots would want to keep anything that would give them a maneuvering advantage (no matter how small) so I might vote for the TVC for the WVR fight.

But with the collective perception in this thread, plus the decreasing need for extreme maneuverability for the WVR fight (better and better HOBS missiles, fewer WVR engagements), plus added cost/complexity/weight, I wonder if TVC will be passed over for 6th-gen fighters.

jetnerd wrote:

wrightwing wrote:

The effect would be negligible. It'd have less post stall and high altitude agility, and a bit more drag while supercruising, but its pre stall performance would be relatively unchanged.

I would guess that pilots would want to keep anything that would give them a maneuvering advantage (no matter how small) so I might vote for the TVC for the WVR fight.

But with the collective perception in this thread, plus the decreasing need for extreme maneuverability for the WVR fight (better and better HOBS missiles, fewer WVR engagements), plus added cost/complexity/weight, I wonder if TVC will be passed over for 6th-gen fighters.

No, it will be there because the desire is for 6 gen aircraft to be able to loiter in enemy territory. This means that control surfaces should be eliminated in order to get RCS even lower. The TV will probably be in a form other than actually moving a nozzle though.

What other form would that come in if the nozzle doesn't do it?

There have been studies that inject cold air (bleed air from the compressor section) around the edges of the nozzle and it can cause a +-20 degree swing in thrust direction, IIRC.

shingen wrote:

No, it will be there because the desire is for 6 gen aircraft to be able to loiter in enemy territory. This means that control surfaces should be eliminated in order to get RCS even lower. The TV will probably be in a form other than actually moving a nozzle though.

Would there be backup controls in case of engine failure?

WE HAVE A WINNER!! hobbyist you just hit the nail on the head as to why an all TVC airframe is a bad idea.

Spud - that's an interesting concept and sounds pretty good if it works.

As for the engine quitting, I'd assume that any platform would have to have at least enough flight control surface to limp home with engine issues.

SpudmanWP wrote:

There have been studies that inject cold air (bleed air from the compressor section) around the edges of the nozzle and it can cause a +-20 degree swing in thrust direction, IIRC.

yupp, but you need a lot of bleed air to make it work, don't remember any figures, but it's a lot.
And: the time that you need the most control authority is at approach, and then your engine usually is at low thrust....
IMHO Rudders and ailerons are always better.

sprstdlyscottsmn wrote:

WE HAVE A WINNER!! hobbyist you just hit the nail on the head as to why an all TVC airframe is a bad idea.

Well, if all the engines failed over enemy territory, ailerons and elevators wouldn't help you anyway. TVC maneuvering is more less the same risk as running 1 engine.

exorcet wrote:

sprstdlyscottsmn wrote:

WE HAVE A WINNER!! hobbyist you just hit the nail on the head as to why an all TVC airframe is a bad idea.

Well, if all the engines failed over enemy territory, ailerons and elevators wouldn't help you anyway. TVC maneuvering is more less the same risk as running 1 engine.

ailerons and elevators would still give some control authority, even with engine failure. The plane with only TVC would immediately be out of control.

I suppose so, but I was implying that the plane would be lost, TVC controls or not [ it's over enemy territory with no power]. If the engine dies on takeoff or near a friendly base, then having aero controls would be a great help.

Forum: General F-22A Raptor forum

F-22 without thrust vectoring