Chinese carrier-borne AEW&C testbed - Xian KJ-600

[Woody]

Hi guys,

You've probably already seen this but I'd be interested in your opinions and anymore information you may have (Deino?). It's not a particularly glamorous airframe but very interesting because of what it could represent.

http://www.flightglobal.com/news/articles/pictures-images-emerge-of-possible-chinese-carrier-borne-aewc-testbed-374858/

Cheers, Woody

(Moderators: if it's already been discussed please edit as you see fit)

 

[NUSNA_Moebius]

(in link) The existence of the JZY-01 could suggest that China eventually intends to develop aircraft carriers equipped with steam or electro-magnetic catapults.

First of all, not surprised to see an E-2 clone. I'm not surprised one bit.

But more importantly, is developing a proper catapult so difficult? To this day, I'm still surprised that none of the Soviet/Russian carriers or the new converted Indian carrier have a catapult on the end of the angled deck for heavier aircraft and heavy loaded combat aircraft.

 

[hole in the ground]

But more importantly, is developing a proper catapult so difficult? To this day, I'm still surprised that none of the Soviet/Russian carriers or the new converted Indian carrier have a catapult on the end of the angled deck for heavier aircraft and heavy loaded combat aircraft.

Is it a question of developing a catapult or developing an aircraft to utilise one? Perhaps you can get more commonality with purely land based aircraft if you ramp launch and not cat? You are still arresting the landing so i would assume that the aircraft have got to be stressed for that. But I have never designed a carrier aircraft so again perhaps designing for arrested landing is simpler than the stresses for launch.

 

[Bill Walker]

From work done many years ago on landing gear design for carrier based aircraft, the landings are easier than a catapult launch (from a landing gear designers point of view, anyway). That assumes a tow bar launch, and not a bridle launch (which imposes its own weight penalties on the aircraft, plus throws away bridles). Also, the failure modes of a ramp are much less demanding than the failure modes of a catapult. The US has been trying for decades to come up with a non-steam catapult, but it is still a long ways from service use.

 

[Jemiba]

... plus throws away bridles...

Nitpicking, of course, but during the times of "Phantomisation" of the RN Carriers already, about
15 £ of british taxpayers money were saved by the installation of the "bridle catcher", later
used on USN carriers, too.
http://www.flickr.com/photos/30224926@N02/5656185521

 

[NUSNA_Moebius]

Considering the much longer take off distance used for heavier loaded/less powerful aircraft on ski-ramp carriers (200m?), I would say a catapult is still a good thing to have. With one in front, you can keep those operations well forward, and out of the way of aircraft landing, though it would compromise having a ski-ramp (but it wouldn't even be needed if you have a catapult).

 

[Hood]

Some recent developments. As ever, hard to tell if Flightglobal are falling for fandom art of if this is the genuine article.
An AEW and COD aircraft seems obvious for the Type 002 class if it has catapults but an ASW variant seems odd. No navy now operates carrier-based fixed-wing ASW and I would have thought helicopters would have been the better solution.

https://www.flightglobal.com/news/a...out-beijings-aircraft-carrier-ambitio-458339/

 

[stealthflanker]

I'm more curious on the radar being used. Wonder if Chinese will opt for E-2D concept by using UHF band or opt for higher frequencies.

 

[Foo Fighter]

Some recent developments. As ever, hard to tell if Flightglobal are falling for fandom art of if this is the genuine article.
An AEW and COD aircraft seems obvious for the Type 002 class if it has catapults but an ASW variant seems odd. No navy now operates carrier-based fixed-wing ASW and I would have thought helicopters would have been the better solution.

https://www.flightglobal.com/news/a...out-beijings-aircraft-carrier-ambitio-458339/

Would that not depend on how far out from your carriers you want an ASW barrier?

 

[Deino]

Finally a clear image ...

 

[Hood]

I usually hate it when people say "they've copied it" but basically "they've copied it". Apart from the having a taller upper fin section and shorter lower fin section (the E-2D is vice-versa) and flatter wing tips this could be 100% mistaken for an E-2D, the rotodome support structure and even the rear of the engine nacelles and undercarriage doors look 100% identical. Even the tiny antennas on the tail cone look identical!!

 

[Deino]

I usually hate it when people say "they've copied it" but basically "they've copied it". Apart from the having a taller upper fin section and shorter lower fin section (the E-2D is vice-versa) and flatter wing tips this could be 100% mistaken for an E-2D, the rotodome support structure and even the rear of the engine nacelles and undercarriage doors look 100% identical. Even the tiny antennas on the tail cone look identical!!

I agree ... I hate this too, since copying - especially when not having the real original one at hand - is not an easy task, but as it seems, here we can indeed call it a "copy" even with certain differences on the nose, tail, radar-mount ...

 

[Trident]

Never mind the undercarriage doors, the undercarriage itself is identically configured (inward facing tires, rear facing torque link position - no reason why either absolutely HAS to be that way). From Deino's excellent comparison photos, the explanation for the "inverted" fin area distribution could be a relatively taller radome support in combination with lower HTP dihedral. Possibly the E-2 configuration is a legacy of being designed to fit lower hangar ceilings on older CVs?

Will be interesting to see (if we haven't already?) how the wing fold mechanism is implemented - Yak-44 style or again the same solution as on the Hawkeye.

 

[sferrin]

Even has the same mint primer. Bet the can it came out of even says, "PP&G" on the outside.

 

[Trident]

Well, before that formulation became available, virtually everybody was using the "same" yellow primer There are many reasons to think this is more of a copy than can be considered decent or convergent evolution, but the colour isn't one of them.

 

[Deino]

Another one ...

 

[CJGibson]

View: https://www.youtube.com/watch?v=M8XQV0PYf3c


Chris

 

[sferrin]

Well, before that formulation became available, virtually everybody was using the "same" yellow primer There are many reasons to think this is more of a copy than can be considered decent or convergent evolution, but the colour isn't one of them.

So they just coincidentally changed primer at the same time that "just happens" to be the same exact color? Really?

 

[Foo Fighter]

There have been more than a few operators. I would suggest one of them or more, has passed an airframe or two to the PRC. Oddly enough, several of those operators have a history of cooperation with the PRC too.

 

[TomS]

There have been more than a few operators. I would suggest one of them or more, has passed an airframe or two to the PRC. Oddly enough, several of those operators have a history of cooperation with the PRC too.

I'd be surprised if we can't account for all of the export E-2 airframes. There aren't that many. Who do you suppose are the cooperators who handed one over to China? Israel? Singapore? The French?

But come on, there is a literal baker's dozen of E-2 airframes on display in museums or as gate guards. And who knows how many walk-around photo sets from airshows. That's all that's needed to get to this level of similarity.

 

[Foo Fighter]

Not suggesting the aircraft remained in PRC hands but on public display is one thing, being able to have the aircraft somewhere to microscopically inspect the aircraft is another. 3d Scanng of something that size can be done but it would require privacy.

 

[TomS]

Not suggesting the aircraft remained in PRC hands but on public display is one thing, being able to have the aircraft somewhere to microscopically inspect the aircraft is another. 3d Scanng of something that size can be done but it would require privacy.

Yes. But I don't think it's quite such a precise copy that 3-D laser scanning would be needed. You can see subtle profile and shape differences throughout (the nacelles especially, but also things like the trailing edge of the rotodome pylon, etc.). I suspect that if you actually put a ruler on the various parts, nothing but some off-the-shelf components would be exactly the same. That suggests to me that they were consciously following the E-2 pattern but tweaking as they went.

 

[TomcatViP]

I am pretty sure they didn't even try to replicate the audacious curves of the rear fuselage. Have a look at an E-2 in a museum, that's probably the most beautiful piece of stressed skin I have seen (on an airplane).

Let's hope that a certain head of state from Europe was not tricked in ordering the Chinese copy...

 

[riggerrob]

I usually hate it when people say "they've copied it" but basically "they've copied it". Apart from the having a taller upper fin section and shorter lower fin section (the E-2D is vice-versa) and flatter wing tips this could be 100% mistaken for an E-2D, the rotodome support structure and even the rear of the engine nacelles and undercarriage doors look 100% identical. Even the tiny antennas on the tail cone look identical!!

I agree ... I hate this too, since copying - especially when not having the real original one at hand - is not an easy task, but as it seems, here we can indeed call it a "copy" even with certain differences on the nose, tail, radar-mount ...

"If you don't understand something, copy it exactly." said parachute designer Sandy Reid (Rigging Innovations).

 

[F.L.]

How will this plane take could off with a Skyjump ? I thought that this was only usable for fighters.

 

[NUSNA_Moebius]

How will this plane take could off with a Skyjump ? I thought that this was only usable for fighters.

Nose gear has what looks to a catapult bar.

 

[F.L.]

How will this plane take could off with a Skyjump ? I thought that this was only usable for fighters.

Nose gear has what looks to a catapult bar.

But the Chinese don't have catapult-equipped aircraft carriers.

 

[aim9xray]

Hmmm. I'd rate it highly likely that the aircraft implemented the Grumman Sto-Wing design based on these photos. The tell is the small probe at the junction of the horizonatal and outboard vertical stabilizers. This is for the retractable mechanism in the bottom of the wing to latch and lock on to after the wing fold process.

 

[NUSNA_Moebius]

How will this plane take could off with a Skyjump ? I thought that this was only usable for fighters.

Nose gear has what looks to a catapult bar.

But the Chinese don't have catapult-equipped aircraft carriers.

They’ve been experimenting with CATOBAR type aircraft on land and developing the necessary equipment for a while now, in particular an EMALS equivalent.

 

[TomS]

How will this plane take could off with a Skyjump ? I thought that this was only usable for fighters.

The USN tested the E-2C from a shallow ramp in the 1980s, and there's a rumor that NG tested it from a 12-degree ramp in 2005, for an Indian proposal.

https://www.secretprojects.co.uk/threads/grumman-e-2-hawkeye.22239/#post-518551

This link suggests it might have just been a paper study, which seems more likely.

The Tale of the Indian Navy and the E-2 Hawkeye 2000 - Livefist

Just over two years ago, HAL signed an agreement with Northrop Grumman Corp. to “work together on projects of mutual benefit”. This, their press release at the time said, would result in getting HAL on board the E-2C Hawkeye aircraft carrier-based airborne early warning and control (AEW&C)...

www.livefistdefence.com

 

[Foo Fighter]

I am certain that if you take a look at Soviet copies of the B-29, you will find similar differences from the original. Trying to make parts simpler and cheaper to create/construct.

No 3d scanning then but they did have the aircraft for as long as they wanted them.

 

[Trident]

The Yak-44 was designed to also operate from the ski-jump Kuznetsov class carriers, but then the D-27 propfans gave it a frankly ridiculous power to weight ratio. Fairly sure the Chinese engine can't match that, so if it is able operate without a catapult, TOW and thereby endurance will probably be severely limited.

Hmmm. I'd rate it highly likely that the aircraft implemented the Grumman Sto-Wing design based on these photos. The tell is the small probe at the junction of the horizonatal and outboard vertical stabilizers. This is for the retractable mechanism in the bottom of the wing to latch and lock on to after the wing fold process.

 

[GTX]

I'd be surprised if we can't account for all of the export E-2 airframes. There aren't that many. Who do you suppose are the cooperators who handed one over to China? Israel? Singapore? The French?

Really?

 

[TomS]

I'd be surprised if we can't account for all of the export E-2 airframes. There aren't that many. Who do you suppose are the cooperators who handed one over to China? Israel? Singapore? The French?

Really?

Sorry, I'm not sure what you're asking.

For clarity, I think these are unlikely.

 

[Bounce]

How will this plane take could off with a Skyjump ? I thought that this was only usable for fighters.

Nose gear has what looks to a catapult bar.

But the Chinese don't have catapult-equipped aircraft carriers.

They will, CV-18 which is an EMALS carrier is currently in fitout having just been launched.

 

[helmutkohl]

I think it could be entirely plausible that they didn't have access to an entire E-2 physically.
it could be similar to the Ilyushin Il-62 and the Vickers VC10, where they looked extremely similar leading to unverified claims of copying
but likely that the engineers of the Il-62 did their best to imitate the VC10, but like in many similar cases, can't get it fully right either, leading to something that internally (avionics, structure, materials) to be very different.

 

[Deino]

How will this plane take could off with a Skyjump ? I thought that this was only usable for fighters.

Nose gear has what looks to a catapult bar.

But the Chinese don't have catapult-equipped aircraft carriers.

Not yet in service, but as it seems, the Fujian is currently preparing for its first cruise this summer.

 

[TomS]

I think it could be entirely plausible that they didn't have access to an entire E-2 physically.
it could be similar to the Ilyushin Il-62 and the Vickers VC10, where they looked extremely similar leading to unverified claims of copying
but likely that the engineers of the Il-62 did their best to imitate the VC10, but like in many similar cases, can't get it fully right either, leading to something that internally (avionics, structure, materials) to be very different.

Agreed. Also, note that the KJ600 is longer and wider in wingspan than the E-2C by a good half meter in each direction. So it's not a direct near-copy like the Tu-4 and B-29.

 

[mkellytx]

I usually hate it when people say "they've copied it" but basically "they've copied it". Apart from the having a taller upper fin section and shorter lower fin section (the E-2D is vice-versa) and flatter wing tips this could be 100% mistaken for an E-2D, the rotodome support structure and even the rear of the engine nacelles and undercarriage doors look 100% identical. Even the tiny antennas on the tail cone look identical!!

Or maybe very similar requirements end up driving very similar solutions…. It isn’t as if carrier borne AEW aircraft have a pretty unique set of requirements. Nothing wrong with using a configuration that you know already works because it’s been flying for over 50 years. Now if the structural design under the skin is the same…

 

[TomS]

Or maybe very similar requirements end up driving very similar solutions…. It isn’t as if carrier borne AEW aircraft have a pretty unique set of requirements. Nothing wrong with using a configuration that you know already works because it’s been flying for over 50 years. Now if the structural design under the skin is the same…

Similar requirements is how you get the Yak-44. But the KJ-600 is way closer than that. It's clearly designed to closely model the E-2C, just tweaked in a few places.