Yeah wing design can make a small difference in terms of induced drag at low speed, but we are talking about a class of aircraft that generally all have pretty high wing loading across the board, so I’d hesitate to use this as a very important discriminant in the comparison.

That’s not quite true. The real factor to be considered is excess thrust, which is thrust – drag. Yes, the F-15 has a much higher T/w ratio than the F-14, but at high AoA (read, high G turn) the F-14 has much lower drag thanks to its larger aspect ratio and span efficiency. The drag efficiency is especially pronounced at mid-low altitude at high-subsonic/low-transonic part of the flight envelop, where the Tomcat can fully spread its wings.

Sorry ? F-35 has an “S-duck”? No it doesn’t, it’s just a single engine aircraft , with side intakes. That’s not one of these bloody “S-ducks” everyone is mental about either.;)

So…you’re saying single engine aircraft with side intakes cannot possibly have an S-duct?

Trident, I can agree with that, the main focus of the Su-47 was to test forward swept wings – with the added bonus of learning more about S-ducts at high alphas. The thing is, the Su-47 only flew for 150 hours or so in its original flight test programme, barely enough to gain data on the basic aerodynamics. The Grumman X-29 flew 436 sorties in its programme.

I can’t help thinking that nothing was learnt from the Su-47 that wasn’t already learnt from the X-29?:confused:

The Su-47 would have been a very wasteful project for a tech demo. Think about it, why do a twin engine heavy weight fighter configuration when you could just modify a lighter aircraft (like the Americans did.) It’s not like the Russians had a lot more money to burn than the Americans.

In every aspect the Su-47 was as serious as a prototype fighter could possibly be. Had the Russians not decided to change their mission requirements a decade ago the Berkut may well have gone through flight tests and be on its way to production.

When Sukhoi learned that the Su-47 could no longer meet all the requirements (VLO, range, speed, etc), not without some fundamental change in its design, they went back to the drawing board and made T-50, and reuse the Su-47 airframe for other testing.

Given what just happened to T-50 not long ago, I believe that is a very necessary and good practice.

What happened to T-50 not long ago was it smoothly aborted a take off after an engine surge.

My suspicion is the drogue chute cylinder is coupled with the landing gears on the J-20 and only retracts when the landing gears are retracted.

The intake is straight and it ain’t stealth

TROLL

Hmm, does this decisively end the debate on intake curvature? Seems like there is curvature in the horizontal and vertical plane.

USS.

Don’t let the upper surface curvature fool you.

And isn’t there already a j-20 thread 6?

That’s what I’m thinking as well. There are just way too many J-20 threads. Can someone please clean this up?