J-20 5th Gen Fighter Thread IV (Closed to posting)

[Jeff Head]

Point of order: the F-35 does have side bays.

No. It does not. It has two bays on the bottom, one to each side just off the centerline.

With the Block V builds (and perhaps before) which will be the full production builds, those bays will hold both JDAMs (perhaps up to 2,000 lbs) and two AMRAAM missiles in each bay...the missiles with special fins for the F-35 so they can fit on the bay doors and be launched from them when opened as necessary and the JDAM down in the bay.


Witht he doors closed, the missiles fold down over the top of the JDAM in each bay.

But there are no side bays.

This how the early production and now Low Rate Production models look:

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This is how the full production models will look:

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[Engineer]

Post stall is not useless, that is just a mere myth, what really happens is now they have HHOBS and DAS, you do not need now to be ultra agile, your missiles will do it for you, your helmet mounted sight will do it for you, so TVC simple becomes an aid at supercruise and and aid for stealth.

In fact the victories of Eurofighter over Su-30MKI are due to HHOBS

Indeed, the statement "post-stall is not useless" is a myth since post-stall is tactically useless. We have a video of

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. The transcript is as follow:

The F22 can sustain a turn rate of 28 deg per second at 20,000 feet while the F-15 can get an instantaneous rate of 21 and a sustained rate of 15-16 degrees. So you are pulling and hoping. Post stall, maneuver, the ass end drops and instead of going up, it just drops in mid air and the airplane will rotate with its nose up. This is where the Eagle or Viper pilot would pull up vertical, switch to guns, then come down and take a shot at the F-22. Of course you have to first get in close to do this, most probably the F-22 will kill you before that.

The Su-30? No problem. Big airplane. Big cross section. Jamming to get to the merge, so you have to fight close... he has 22 - 23 degrees per second sustained turn rate. We've been fighting the Raptor, so we've been going oh dude, this is easy. So as we're fighting him, all of a sudden you'd see the ass end kick down, going post stall - but now he starts falling from the sky. The F-15 wouldn't even have to pull up. slight pull up on the stick, engage guns, come down and drill his brains out.

Let us also see an Eurofighter pilot's opinion on thrust vectoring. This is taken from

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:

Thrust Vectoring is one of the design elements that can contribute to create a certain advantage during close air combat by generating impressive pitch and yaw rates, but only in a limited portion of the flight envelope at velocities well below “corner speed”.

However, Thrust Vectoring can also transform in a few seconds an energy fighter in a piece of metal literally falling off the sky, making it an easy prey for those who have been able to conserve their energy.

Moreover, Thrust Vector operation requires the pilot to “create the opportunity” for its usage, spending valuable time in manoeuvring the aircraft to achieve a suitable condition and managing the activation of the Thrust Vector Control.

The pilot then went on about the situations where the aircraft is in offensive, neutral, and defensive positions. In none of the situations does thrust vectoring provides a tactical advantage.

If you are “defensive” and your aircraft has Thrust Vectoring, you can possibly outturn your enemy, but that most likely won’t prove to be a great idea: an energy fighter like the Typhoon will conveniently “use the vertical” to retain energy and aggressively reposition for a missile or gun shot. Also the subsequent acceleration will be extremely time (and fuel) consuming, giving your opponent the opportunity to tail chase you for ever, exploiting all its short range weapon array.

If you are “neutral”, when typically vertical, rolling and flat scissors would accompany the progressive energy decay, similarly performing machines would remain closely entangled, negating the opportunity for Thrust Vector activation.

If you are “offensive”, probably stuck in a never ending “rate fight”, Thrust Vector could provide the opportunity for a couple of shots in close sequence. Make sure nobody is coming to you from the “support structure”, otherwise that could be also your last move.

 

[latenlazy]

Indeed, the statement "post-stall is not useless" is a myth since post-stall is tactically useless. We have a video of

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. The transcript is as follow:


Let us also see an Eurofighter pilot's opinion on thrust vectoring. This is taken from

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:


The pilot then went on about the situations where the aircraft is in offensive, neutral, and defensive positions. In none of the situations does thrust vectoring provides a tactical advantage.

Wouldn't this imply that TVC could be decisive if both fighters have bled most of their energy in a prolonged engagement?

 

[plawolf]

Wouldn't this imply that TVC could be decisive if both fighters have bled most of their energy in a prolonged engagement?

Very unlikely for two good pilots to get themselves in such a situation, as they would both be sitting ducks if there was anyone else nearby.

TVC could make a big difference if you and your target were the only two planes in the sky. But in a realistic combat scenario, there will be other fighters about, and the last thing you want is to be caught without any energy.

 

[latenlazy]

Very unlikely for two good pilots to get themselves in such a situation, as they would both be sitting ducks if there was anyone else nearby.

TVC could make a big difference if you and your target were the only two planes in the sky. But in a realistic combat scenario, there will be other fighters about, and the last thing you want is to be caught without any energy.

What about two bad pilots

Well, at least we've figured out which domains TVC might be useful for. Whether that's worth the developmental effort and trade offs for the PLA is anyone's guess?

 

[MiG-29]

Very unlikely for two good pilots to get themselves in such a situation, as they would both be sitting ducks if there was anyone else nearby.

TVC could make a big difference if you and your target were the only two planes in the sky. But in a realistic combat scenario, there will be other fighters about, and the last thing you want is to be caught without any energy.

TVC nozzles increase turn rates, so not everything is post stall.

This means the fighter like Su-30MKI has increased ITR and STR.

However few here want to see what is HHOBS, which stand for helmetless high offbored capability.

Eurofighter has HHOBS as well Rafale, while F-22 has not.
It will be until later in the decade that F-22 will have HHOBS, why the F-22 pilots want HMS? well simply add a HMS and the F-22 will exploit the AIM-9X to the fullest, meaning full engagment capability or in few words it can fire the missile at targets behind as well in front of the pilot without turning and keeing a straight flight path, in few words it does not need turning to hit a target.


When the Missile head seeker is inside the weapons bays, the AIM-9X head seeker is blind, it needs data link input to know where is the intendet target, in the J-20 they have that missile rail out the weapons bay even when the bay door is closed.


Rafale and Eurofighter have not such problem since the missile is out on external weapons bays, the head seeker will be able to cue automatically.

Post stall is still useful but not like 20 years ago, F-22 versus Eurofighter demostrated that since AIM-9M has not HHOBS or fire over the shoulder capability but IRIS-T has that capability, plus F-22 lacks HMS while the Rafale and Eurofighter have HMS and Spectra data link cueing systems.


J-20 does not need TVC nozzles if it has a good HHOBS system.

 

[latenlazy]

TVC nozzles increase turn rates, so not everything is post stall.

It's meaningless to talk about turn rates without also talking about turn rates at specific speeds.

 

[MiG-29]

It's meaningless to talk about turn rates without also talking about turn rates at specific speeds.

we are not comparing, i am just saying that if a fighter has a max ITR of 30 deg/s, it will increased with TVC nozzles around 10%.

So the benefits are not just post-stall but also turn rates.

This tell you that F-22 has increased turn rates thanks to its TVC nozzles.

But that advantage is now less important with HHOBs that allows full engagement capability or 360 degrees of off bored capability or in other words full sphere.

 

[latenlazy]

we are not comparing, i am just saying that if a fighter has a max ITR of 30 deg/s, it will increased with TVC nozzles around 10%.

So the benefits are not just post-stall but also turn rates.

This tell you that F-22 has increased turn rates thanks to its TVC nozzles.

But that advantage is now less important with HHOBs that allows full engagement capability or 360 degrees of off bored capability or in other words full sphere.

Establishing a turn rate without also establishing at what speed it can maintain that turn rate, and what the speed penalties are for achieving that turn rate are all meaningless if we're trying to measure performance. Turn rates alone tell us nothing without proper context.

 

[Munir]

Establishing a turn rate without also establishing at what speed it can maintain that turn rate, and what the speed penalties are for achieving that turn rate are all meaningless if we're trying to measure performance. Turn rates alone tell us nothing without proper context.

Exactly. If you use TVC, which forces the nose to move extra, it will result in extra drag cause the rest of the body is resisting it. So often it is handy in low speed and high AOA but STR is a different story. Then again why would you add so much weight (TVC) if you do NOT want to go close in with your very very expensive stealth? F22 is intermediate solution between a optimized stealth and air superiority fighter. Just look at the next generation of stealth.