Ask anything Thread (Air Force)

[Nx4eu]

Could it be possible and why haven't countries create AWACS platforms based on bomber airframes, ie a H-6 AWACS derivative. Is it due to the lack of space internally due to it's slim profile or is it lack of power generation. With the lack of jet powered AWACS in the PLAAF I'd imagine it'd be pretty attractive considering specifications in endurance and speed.

 

[lcloo]

Could it be possible and why haven't countries create AWACS platforms based on bomber airframes, ie a H-6 AWACS derivative. Is it due to the lack of space internally due to it's slim profile or is it lack of power generation. With the lack of jet powered AWACS in the PLAAF I'd imagine it'd be pretty attractive considering specifications in endurance and speed.

If you make a search on early AWACS you will find a few examples of AWACS based on bombers. A 1969 Chinese example is KJ-1, based on Tupolev TU-4 bomber, though the project was abandoned due to unmatured radar technology. USSR also attempted to built EWACS based on bomber but found the internal space too small for equipment and human operators, they switched to passenger jet.

Modern day EWACS are mostly based on commercial airline airframes for the generous internal space and also pressurised passenger cabin vs relatively narrow and non-pressurised weapon bay of a bomber.

Advantages of using passenger aircrafts are
1. Endurance and range, example you can fly from Beijing to London non-stop with-out aerial refueling.
2. Pressuried and air-conditioned comfort and large internal space provides much better working condition for pilots and operators, resting spaces, prevents fatigue and other amenities.
3. Ease of conversion. Compare to the complex internal structure of a bomber which are designed to fit bomb and missile racks, fuel cells, landing gear comparment, bulkheads etc, passenger jets have simple clean cabin to work with.

 

[Raison D'tere]

I hope this is the right place to ask this, but how does the J20 compare to its 5th gen counterparts, particularly in its supermaneuverability? I do understand that such close engagements are rarely possible given awacs, systems, missiles etc, however, it would be better pr at airshows to showoff those moves (although I feel that's not the way of the PLAAF).

As such, is it possible for the J20 to do everything the Su57 does, like post stall maneuvers? Or is the airframe not built for that?

 

[Alfa_Particle]

I hope this is the right place to ask this, but how does the J20 compare to its 5th gen counterparts, particularly in its supermaneuverability? I do understand that such close engagements are rarely possible given awacs, systems, missiles etc, however, it would be better pr at airshows to showoff those moves (although I feel that's not the way of the PLAAF).

As such, is it possible for the J20 to do everything the Su57 does, like post stall maneuvers? Or is the airframe not built for that?

Post-stall maneuvers are really just more for show this day and age. For air superiority 5th Gen fighters, maneuverability during supersonic regimes, how good your BVR/HOBS missiles are, are much more meaningful metrics.

But to answer your question directly, the J-20 cannot achieve the same level of subsonic maneuverability as the F-22 or the Felon. It's aerodynamic configuration is made for achieving the same level of supersonic performance of its main counterpart, the F-22, while having inferior engines. That comes at a cost - worse subsonic cruise lift to drag ratio and post-stall maneuverability among other things.

So until the WS-15 is in service, the J-20 can at best achieve the same (or slightly better) level of supersonic performance as the F-22, i.e. best in class, while having potentially inferior transonic performance and almost definitely inferior subsonic and post-stall maneuverability than the F-22 and the Felon.

That doesn't mean it's an absolute slug at low speeds. Far from it. It can still achieve exceptional subsonic maneuverability compared to traditional 4th Gens without TVC, it's just that the F-22 and the Felon are brilliant at those speeds.

However, with the J-20A, that's an entirely different story. We're looking at potentially the undisputed king during supersonic and transonic performance (thanks to it's overcompensating aerodynamic design, now with perhaps the overall best 5th generation engine), and extremely formidable also during subsonic speeds (the vanilla J-20 tbh can already deal with the others with the PL-10 already even with worse post-stall maneuverability).

 

[Alfa_Particle]

I hope this is the right place to ask this, but how does the J20 compare to its 5th gen counterparts, particularly in its supermaneuverability? I do understand that such close engagements are rarely possible given awacs, systems, missiles etc, however, it would be better pr at airshows to showoff those moves (although I feel that's not the way of the PLAAF).

As such, is it possible for the J20 to do everything the Su57 does, like post stall maneuvers? Or is the airframe not built for that?

You know what? On second thought, the vanilla J-20's low speed nose authority is actually pretty damn good too.

See:

Ignore the stupid title, but it shows that even during extremely low airspeed (it was practically suspended in air), the J-20's roll rate is still very good. Would be great if there's something else to compare it too tbh.

With the WS-15s, the J-20A might actually give the F-22/Su-57 an extremely hard run for their money during low speeds.

 

[siegecrossbow]

You know what? On second thought, the vanilla J-20's low speed nose authority is actually pretty damn good too.

See:

Ignore the stupid title, but it shows that even during low airspeed, the J-20's roll rate is still very good. Would be great if there's something else to compare it too tbh.

Not just roll rate. It could maintain control well even under high AOA low speed conditions, which is not the area of flight envelope the design optimizes a lot for. Most aircraft will stall under similar conditions. I know that people hate the ventral stakes but they really do serve an important purpose.

 

[Alfa_Particle]

Not just roll rate. It could maintain control well even under high AOA low speed conditions, which is not the area of flight envelope the design optimizes a lot for. Most aircraft will stall under similar conditions. I know that people hate the ventral stakes but they really do serve an important purpose.

Man, it really sucks that we probably won't ever see it pull some insane moves with WS-15 TVC in airshows.

The ventral strakes are actually quite smart tbh. Given if they're fully made from RAM composites, they practically have no impact on RCS AND helps concealing the IR signatures and the nozzles.

 

[siegecrossbow]

Man, it really sucks that we probably won't ever see it pull some insane moves with WS-15 TVC in airshows.

The ventral strakes are actually quite smart tbh. Given if they're fully made from RAM composites, they practically have no impact on RCS AND helps concealing the IR signatures and the nozzles.

It is a part of the trade offs. Before the A variant only the “middle” of the strake is made of special material but that has since changed, no doubt owing to advances in material. From a side profile the J-20 probably has the lowest RCS of extant stealth fighters due to small vertical control surfaces plus the fact that vertical slabs don’t form corner reflectors with the horizontal slabs or the main wings.

 

[iBBz]

You know what? On second thought, the vanilla J-20's low speed nose authority is actually pretty damn good too.

See:

Ignore the stupid title, but it shows that even during extremely low airspeed (it was practically suspended in air), the J-20's roll rate is still very good. Would be great if there's something else to compare it too tbh.

With the WS-15s, the J-20A might actually give the F-22/Su-57 an extremely hard run for their money during low speeds.

What authority? Its just a roll at speeds that are too low even for dogfighting. The J-20 clearly struggles to put on a show during events, because it can't. It wasn't designed for that. There are zero videos of it pulling off any moves that are even remotely close to what the F-22 and Su-57 can do. Have you even seen what these two can do in airshows?

Increasing thrust without thrust vectoring doesn't help maneuver harder. It just helps replenish lost energy at a higher rate so the plane continues to dogfight without losing speed. The maneuvering part will still rely entirely on the plane design, which in the case of the J-20, a long-arm delta canard, a design that is to be avoided when designing for high-g maneuvering.

 

[siegecrossbow]

What authority? Its just a roll at speeds that are too low even for dogfighting. The J-20 clearly struggles to put on a show during events, because it can't. It wasn't designed for that. There are zero videos of it pulling off any moves that are even remotely close to what the F-22 and Su-57 can do. Have you even seen what these two can do in airshows?

Increasing thrust without thrust vectoring doesn't help maneuver harder. It just helps replenish lost energy at a higher rate so the plane continues to dogfight without losing speed. The maneuvering part will still rely entirely on the plane design, which in the case of the J-20, a long-arm delta canard, a design that is to be avoided when designing for high-g maneuvering.

Typhoon is also long arm canard. This is not to mention that in CCTV interviews the Brigade commander from Anshan confirmed that J-20 WS-10 maneuvers better than J-11B and that it can sustain 9G maneuvers for around 10 seconds, and new pilots train for that. Even AL-31 equipped J-20 maneuver on par with J-10A as per test pilot Li Gang.