Wish List: DCS Nanchang CJ-6

[LowRider88]

The JustFlight mod market for the FSX sim has a Nanchang CJ-6 mod available for that sim.

That mod was made by someone from inside China.

It seems to have a complete external and cockpit model and perhaps a reasonable FM.

Would it be possible for Deka to partner with this individual to translate his work into DCS?
It would be great if Deka could work their magic, check the documentation, ensure the accuracy, and perhaps add different variants of the CJ-6, like the standard trainer, the single seater, and the armed version with guns.

Since this individual did most of the work, perhaps this could be a great partnership and a quick win for Deka, as there is much love for this aircraft around the world, and would surely sell well, since it partners well with the existing DCS Yak-52.

 

Some videos for inspiration -

 

Nanchang CJ-6 Documentary:

 

Nancy Chang Walkaround:

 

CJ-6 at air shows:

A Xinjiang actress, an Olympic swimmer and other native celebrities flying the CJ-6:

CJ-6 vs Yak-52 at air races:

CJ-6 getting a second life as a world wide sports plane:

 

Edited February 20, 2023 by LowRider88

[PLAAF]

If we are going to get a trainer, I rather have one with more capability, like L-15.

 

[LowRider88]

1 hour ago, PLAAF said:

If we are going to get a trainer, I rather have one with more capability, like L-15.

 

I would like the L-15 also.

But taking into consideration that they will be focusing mainly on the development of the J-8II now, if they were willing and able to take on a side project, which one would be cheaper and easier to deliver sooner, and might garner even more sales?

The L-15 is a whole new module built from scratch and might have documentation difficulties if the export versions do not differ from the active PLAAF versions.

Instead, a CJ-6 mod has already been built by someone in the area, and just requires some translation and verification, and has publicly available free western manuals available for download:

https://www.manualslib.com/manual/1421073/Nanchang-Cj-6a.html

[motoadve]

The CJ6 flies really nice, I would love to have one in DCS.

This is the one I fly IRL.

 

[LowRider88]

5 hours ago, motoadve said:

The CJ6 flies really nice, I would love to have one in DCS.

This is the one I fly IRL.

 

Nice.  Did it cost you $50k - $100k as mentioned in the walkaround video above?

What line of work do you do to afford a real one?  Do you have to do air shows to pay for it?

[MiG21bisFishbedL]

I've seen prices of CJ-6s fluctuate wildly from $30k up to $400k. It all depends on the fit, finish, and modifications made to the aircraft. Its operational costs are comparable to a lot of popular GA aircraft.

And, for those wondering what's the difference between the CJ-6A and the Yak-52? CJ-15 has a smaller engine derived from the same family. According to my copy of homemade flight reference card, the CJ-6A enjoys a lower fuel burn of ~12gph (45l) @ 150mph (250kmh) with the Yak-52 being a little slower and less efficient with ~150gph (60l) @ 140mph (190kmh).

The CJ-6A is smoother flier than the Yak-52, but the Yak-52 can make your eyes pop out of your noggin with what it can do in terms of aerobatics. Of the other pilots I've met, the Yak-52 can be some what polarizing. A lot love it, others don't care for it. I don't think I've met someone who has flown the CJ-6 and not loved it.

[LowRider88]

1 hour ago, MiG21bisFishbedL said:

I've seen prices of CJ-6s fluctuate wildly from $30k up to $400k. It all depends on the fit, finish, and modifications made to the aircraft. Its operational costs are comparable to a lot of popular GA aircraft.

And, for those wondering what's the difference between the CJ-6A and the Yak-52? CJ-15 has a smaller engine derived from the same family. According to my copy of homemade flight reference card, the CJ-6A enjoys a lower fuel burn of ~12gph (45l) @ 150mph (250kmh) with the Yak-52 being a little slower and less efficient with ~150gph (60l) @ 140mph (190kmh).

The CJ-6A is smoother flier than the Yak-52, but the Yak-52 can make your eyes pop out of your noggin with what it can do in terms of aerobatics. Of the other pilots I've met, the Yak-52 can be some what polarizing. A lot love it, others don't care for it. I don't think I've met someone who has flown the CJ-6 and not loved it.

Great info.
So a low end model is about the cost of an average car?  How much does it cost to store and maintain?

Online sources for metrics seem to vary depending on as you say mods people make on the planes, but from what I was able to calculate from values online, the CJ-6 has better wingloading over the Yak-52.  When you say eye popping performance, is that mainly due to roll and climb rate, and acceleration?  Any experience with their low end stall speeds?

[MiG21bisFishbedL]

It's really going to depend where you hangar, how much work is done on it, how much work is needed, etc. Lots of variables.

As for eye popping, absolutely. Yak-52s are insanely capable as an aircraft that has served as an introduction to aerobatics. And yeah, they stall around 49 knots dirty (90kmh). It gives you plenty of warning with a tail buffet and then a drop of the left wing.

[motoadve]

Hangar average $300, annual $2,000 APROX.

20 GALLONS PER HR WHEN DOING ACRO, 16gph IN CRUISE 

Its a bargain and a lot of airplane for what they cost I paid $73,000 fully restored and nice.

CJ6 has more fuel , is more comfortable and faster than the Yak52, you can find a good Yak52 for $50,000, CJ6 you can do all the warbirds maneuvers its really fun to fly.

Here is mine.

 

 

[MiG21bisFishbedL]

24 minutes ago, motoadve said:

Hangar average $300, annual $2,000 APROX.

20 GALLONS PER HR WHEN DOING ACRO, 16gph IN CRUISE 

Its a bargain and a lot of airplane for what they cost I paid $73,000 fully restored and nice.

CJ6 has more fuel , is more comfortable and faster than the Yak52, you can find a good Yak52 for $50,000, CJ6 you can do all the warbirds maneuvers its really fun to fly.

Here is mine.

 

 

God, I'm jealous. Actually, I just miss owning my own airplane.

[LowRider88]

1 hour ago, MiG21bisFishbedL said:

It's really going to depend where you hangar, how much work is done on it, how much work is needed, etc. Lots of variables.

As for eye popping, absolutely. Yak-52s are insanely capable as an aircraft that has served as an introduction to aerobatics. And yeah, they stall around 49 knots dirty (90kmh). It gives you plenty of warning with a tail buffet and then a drop of the left wing.

By dirty, you gear and flaps down?  Any details about “clean”, and percentage of fuel left?

I found this article that says the CJ-6 clean stall speed (given a very particular situation):

https://www.aopa.org/news-and-media/all-news/2013/july/pilot/east-west-fly-off

Would be cool to see which has better min stall speed.

My rough calculations have the Yak winning when both are near empty, but when fully loaded the CJ wins.

I guess it may be due to the CJ being all metal vs some metal piping in the Yak.

46 minutes ago, motoadve said:

Hangar average $300, annual $2,000 APROX.

20 GALLONS PER HR WHEN DOING ACRO, 16gph IN CRUISE 

Its a bargain and a lot of airplane for what they cost I paid $73,000 fully restored and nice.

CJ6 has more fuel , is more comfortable and faster than the Yak52, you can find a good Yak52 for $50,000, CJ6 you can do all the warbirds maneuvers its really fun to fly.

Here is mine.

 

 

I am jealous too.  That is a slick paint job, and I like that the cockpit is fairly original.  Sounds sweet too.

Man, $70k.  Maybe when I pay off a few things.

In the meantime I guess I have to hope on Deka.  Or get into FSX.

I know, it’s just not the same 

Do you have to do air shows or tours for people to cover the costs?

[LowRider88]

I was reading the wiki article for the CJ-6 and found out that the designers built it because the Yak-18A did not entirely fit their needs.

That is not to say that the 18A is a bad plane, but that just like the Soviet subs, they could not fulfill all the requirements of the Chinese.

I noticed that the Yak-52 and the Yak-18A seem quite similar, more so than the CJ-6 is to either.

So this lead me to think about the different design aspects of the CJ-6 and why those differences mattered to the PLAAF.

I am only an amateur aero dynamicist, so these are only my guesses rather than proven fact.

In terms of external shape differences, here are what I noticed, but more may apply:

• CJ has square tips on wings and tail surfaces, while the Yak has curved
• From nose to tail the Yak’s fuselage is straight at the top and curved on the bottom, while the CJ is more evenly tapered from the rear wing edge to the tail
• CJ has a single flap surface from wing to wing, while the Yak has typical separate flaps
• CJ has flush riveting while the Yak does not
• CJ has trailing link main landing gear, the Yak has straight great legs
• CJ main landing gear folds inward into the wing, while the Yak’s folds forward and protrudes
• Many sources state the CJ is more comfortable and roomier in the cockpit than the Yak
• CJ has dihedral bent wings while the Yak’s wings are straight
• CJ is all metal except for control surfaces, while Yak has a mixed structure

 

Based on these differences, this is my guess as to why the Chinese opted for them.

 

I suspect the main reason may be the Chinese did not have the degree of available fuel as the Soviets may have had.  So they may have designed the CJ to be more fuel efficient and have a longer endurance.  That may be the reason for the flush riveting and the fully retracted landing gear.

But a great design feature of the Yak is that with its gear retracted, it could still belly land and not damage the fuselage and wings, because of this protruding wheels, just like the A-10.

So this may be the reason the CJ was designed with a single long flap running under the body, so that the flap and not the rear gear could take the brunt during a belly landing.

I am not entirely sure why the CJ’s tail slopes down more than the straight back tail, or perhaps up sloping tail of the Yak.  The Yak’s tail does seem more traditional since many planes have that up slope so the tail does not hit the ground during take offs or landings.  Perhaps the CJ uses the evenly sloped and tapered tail for cruise aerodynamics, as a more evenly tapering tail is more like a teardrop shape.  Maybe this helps with efficiency and therefore fuel economy.

I would guess that the down sloping tail might give the rear seater in the CJ a better rear view when looking back as well.

But then the problem would be that the tail is lower, and this could cause the CJ to have more tail strikes than the Yak.  So maybe this is the reason the trailing link main landing gear were used.  If we take the difference in downward slope of the tail between the CJ and the Yak, this difference might be the same as the offset of the trailing links.

The more flatter bottom of the fuselage might have possibly been the reason for the CJ’s more roomier cockpit.  Maybe the flatness allows the cockpit to be extended further back to make more room.

 

There are a few design elements I can’t guess about.

 

For the bent wings, I think the CJ just inherited from the Yak-18.  But then why did the Yak-52 go on to have straight wings?  Maybe that has something to do with landing gear design or for better roll rate.

 

The other is why did the CJ opt for square tip everything?

It does have a vertical tail root extension to give added stability, which in a way could be somewhat equivalent to the Yak’s vertical tail, albeit not curved and smoothed out.

Could it be the square wing tips were to increase aspect ratio, since (according to what I googled) vortices on square tips are to the side, while on curved ones they are on top?  But if so, while make all tips square, instead of just the wings only?

In comparison, I know the BF-109 started out with square wing tips, but then they were extended and rounded later in its service life.  I assume that was because as the plane’s equipment increased over time they had to increase the wing area to keep the same wing loading, and why not copy the Spitfire to an extent.  But then by war’s end, most later planes all went back to square tips.

I googled that the spitfires elliptical wing was best at reducing induced (maneuvering) drag mainly at high altitude.

So why does the Yak stick to curved tips?  Aerobatic planes usually don’t fly as high as the WWII scenarios (the audience would have trouble seeing them).

Anyway, if there are any other amateur, or maybe profession aerodynamicists out there, I would be interested to know your ideas.

[LowRider88]

For anyone who may be interested, here is a good video describing the design aspects of the CJ-6.

Have to turn on Closed Captioned Subtitles:

 

[303_Kermit]

I think these one is much more original and prettier
 

... Today only few flyable planes are available. Soon it will be over, because there are no spare parts (polish aviation industry didn't survive the end of communism). Soon the only place where it will fly can be your PC. And the plane isn't a clone of Yak-52. Engine fuselage and wings - all original.

Edited March 5, 2023 by 303_Kermit

[LowRider88]

6 hours ago, 303_Kermit said:

I think these one is much more original and prettier
 

... Today only few flyable planes are available. Soon it will be over, because there are no spare parts (polish aviation industry didn't survive the end of communism). Soon the only place where it will fly can be your PC. And the plane isn't a clone of Yak-52. Engine fuselage and wings - all original.

 

Thanks for sharing these details.

I didn’t even know of this plane before.  It does look pretty.

In terms of it flying on a PC, I may be biased, but I think the CJ-6 has a better chance.

The numbers don’t lie, the CJ has about 200-300 flying in the US alone, was produced to from 2000-3000 in total, and has a life spanning over 60 years.

So it is a popular plane.  It also already has a mod, for FSX.  There is definitely more interest for it.

Regarding the reason for the TS-8’s short life and low production numbers, according to wiki (I know, debatable), its short life was not due to spare parts, but due to the fact it was soon replaced by jet trainers.  In contrast the CJ has a very long life because it was a very easy to handle, challenging and cost effective trainer, and because it did its job so well even today it is hard to replace it.

I don’t agree with your assessment that the CJ is a copy.  If you look carefully, you can see the only few aspects it shares with the Yak-18 is the engine and the inverted gull wings.  The TS-8 also has inverted gull wings and was completed after the Yak as well.

The entire back section of the CJ is completely different from the Yak, the square tips different, the landing gear different.  It is a unique plane.

I like the sound of the TS-8’s engine, it has a very energetic sound

Edited March 5, 2023 by LowRider88

[303_Kermit]

3 hours ago, LowRider88 said:

Thanks for sharing these details.

I didn’t even know of this plane before.  It does look pretty.

In terms of it flying on a PC, I may be biased, but I think the CJ-6 has a better chance.

The numbers don’t lie, the CJ has about 200-300 flying in the US alone, was produced to from 2000-3000 in total, and has a life spanning over 60 years.

So it is a popular plane.  It also already has a mod, for FSX.  There is definitely more interest for it.

Regarding the reason for the TS-8’s short life and low production numbers, according to wiki (I know, debatable), its short life was not due to spare parts, but due to the fact it was soon replaced by jet trainers.  In contrast the CJ has a very long life because it was a very easy to handle, challenging and cost effective trainer, and because it did its job so well even today it is hard to replace it.

I don’t agree with your assessment that the CJ is a copy.  If you look carefully, you can see the only few aspects it shares with the Yak-18 is the engine and the inverted gull wings.  The TS-8 also has inverted gull wings and was completed after the Yak as well.

The entire back section of the CJ is completely different from the Yak, the square tips different, the landing gear different.  It is a unique plane.

I like the sound of the TS-8’s engine, it has a very energetic sound

 

To be honest I never expected that there will be a polish plane in DCS. It's something specific for my country. A small country - Czech republic can have their own planes and even have them in DCS... Amazing. 

As for short life span of TS-8. It was a military training plane, Yak-52 (and his modified chinese copy ) are civilian planes. After their military service they were pushed to civilian aero-clubs, but they were too big and too expensive for them. Single aircrafts were used until early '80. After the end of communism there were about 2-3 planes kept in private hands. It wasn't easy. Army wasn't interested in selling, and private property (these significant) wasn't possible (and allowed) in Poland until the end of 1980. Miraculously some single planes were rescued, but PZL who produced them exist no more. PZL Mielec was owned first by Sikorsky, then by Lockheed Martin. Production lines are destroyed, nobody makes spare parts for last single flying planes. 4 years ago one of the last planes owned by French "Assotiation pour la sauvegarde du patrimoine aeronautique mondial". To gather parts for renovation whole museums and private collections were asked to help. Next renovation would be probably impossible.

Today there's nothing left from Polish aircraft industry.

Legendary PZL.37 Los (1938y. Laminar wing profile) doesn't exist even in single piece.
PZL.23b Karas doesn't exist even in single piece.
PZL.7 does not exist
PWS.10 does not exist
LWS.6 does not exist
PZL.P-11c last survived plane was rescued by... Herman Göring. Today to see in Krakow. No flyable planes left. Engine is running. It starts once a year, and it's a great rare event.
TS-8 extremely rare
TS-11 once popular, today vanishing rapidly.


All in all I see no point in CJ-6... Consider please some Warbird - some carrier based Japan plane. It will be far more interesting to behold and admire.


Here PZL.P-11c with engine running:

 

Edited March 5, 2023 by 303_Kermit

[LowRider88]

1 hour ago, 303_Kermit said:

To be honest I never expected that there will be a polish plane in DCS. It's something specific for my country. A small country - Czech republic can have their own planes and even have them in DCS... Amazing. 

As for short life span of TS-8. It was a military training plane, Yak-52 (and his modified chinese copy ) are civilian planes. After their military service they were pushed to civilian aero-clubs, but they were too big and too expensive for them. Single aircrafts were used until early '80. After the end of communism there were about 2-3 planes kept in private hands. It wasn't easy. Army wasn't interested in selling, and private property (these significant) wasn't possible (and allowed) in Poland until the end of 1980. Miraculously some single planes were rescued, but PZL who produced them exist no more. PZL Mielec was owned first by Sikorsky, then by Lockheed Martin. Production lines are destroyed, nobody makes spare parts for last single flying planes. 4 years ago one of the last planes owned by French "Assotiation pour la sauvegarde du patrimoine aeronautique mondial". To gather parts for renovation whole museums and private collections were asked to help. Next renovation would be probably impossible.

Today there's nothing left from Polish aircraft industry.

Legendary PZL.37 Los (1938y. Laminar wing profile) doesn't exist even in single piece.
PZL.23b Karas doesn't exist even in single piece.
PZL.7 does not exist
PWS.10 does not exist
LWS.6 does not exist
PZL.P-11c last survived plane was rescued by... Herman Göring. Today to see in Krakow. No flyable planes left. Engine is running. It starts once a year, and it's a great rare event.
TS-8 extremely rare
TS-11 once popular, today vanishing rapidly.


All in all I see no point in CJ-6... Consider please some Warbird - some carrier based Japan plane. It will be far more interesting to behold and admire.


Here PZL.P-11c with engine running:

 

 

Well if you want a Japanese or Polish warbird, why not ask one of those developers who might have any interest in those planes, rather than posting obscure planes in a sub forum for a developer which specializes in Chinese aircraft?

I think you may have better chances that way.  But to be honest I don’t see the appeal in any of these planes.  They weren’t flown for long or even by a variety of nations, and not much impact.  They wouldn’t sell well.  Maybe you can ask a modder?

People in the US refer to the CJ as a warbird.  You can google the YouTube videos.  It definitely has much greater fame and appeal.

[motoadve]

I fly a CJ6 Nanchang, honestly the most fun airplane I have flown in 3,000hrs of flying and 30 different planes including turbo props and some amazing bush planes ,it feels like a warbird, looks like a warbird, sounds like a warbird flies like a warbird, but it wont break your wallet with the fuel economy.

Doing aerobatics or tail chase is a ton of fun, there are more than 200 of those in the USA, and they are a lot more popular than the Yak 52, every owner loves the way they fly, I am very active in the Red Star pilots community, I am sure if they make one, I can get lots of those pilots into flight sims and DCS.

If any developer wants a sample to model the CJ6 in DCS, I will offer mine for sure.

Here is a video of the interior.

 

[303_Kermit]

2 hours ago, LowRider88 said:

Well if you want a Japanese or Polish warbird, why not ask one of those developers who might have any interest in those planes, rather than posting obscure planes in a sub forum for a developer which specializes in Chinese aircraft?

 Probably I didn't expressed myself properly. My fault. What I wanted to point out is; that DCS is a way to immortalize a plane. DCS modules are masterpiece of flight simulation. There's surely couple chinese planes worth of immortalizing. I myself know about couple. Not that I have something against CJ6, but it's not quite what DCS was made for. Q-5, H-5, J-7 (I like to see that one), J-4, J-5... there's probably more

Edited March 5, 2023 by 303_Kermit

[LowRider88]

3 hours ago, motoadve said:

I fly a CJ6 Nanchang, honestly the most fun airplane I have flown in 3,000hrs of flying and 30 different planes including turbo props and some amazing bush planes ,it feels like a warbird, looks like a warbird, sounds like a warbird flies like a warbird, but it wont break your wallet with the fuel economy.

Doing aerobatics or tail chase is a ton of fun, there are more than 200 of those in the USA, and they are a lot more popular than the Yak 52, every owner loves the way they fly, I am very active in the Red Star pilots community, I am sure if they make one, I can get lots of those pilots into flight sims and DCS.

If any developer wants a sample to model the CJ6 in DCS, I will offer mine for sure.

Here is a video of the interior.

 

Those are awesome videos.  Thanks for the cockpit walkaround.

Wow, I see you have a huge video library.

Do you have a CJ startup procedure video also?

I think you are totally right.

With a YouTube celebrity with over 30K subscribers, a whole community of Red Star fans and flyers, available feedback from so many flyers, and available flyers to show off the plane, along with the fact the CJ already has a paid mod on the market, it seems like the CJ would be easy to make and sell in DCS.

[Torbernite]

I'm also afraid that CJ-6 would not touch those more interested in combat mission. But the simpleness makes it possible as a mod, and this topic of trainer is more suitable as a mod. (I mean most lovers come for enthusiasm and preference while those who want an interesting combat aircraft may not buy it.) I think you may find someone willing to do that. Deka seems to have no spare productivity for another primary trainer into DCS. 

2023/2/24 PM1点01分，LowRider88说：

The other is why did the CJ opt for square tip everything?

It does have a vertical tail root extension to give added stability, which in a way could be somewhat equivalent to the Yak’s vertical tail, albeit not curved and smoothed out.

Could it be the square wing tips were to increase aspect ratio, since (according to what I googled) vortices on square tips are to the side, while on curved ones they are on top?  But if so, while make all tips square, instead of just the wings only?

I checked the memoir from Gu Songfen (aerodynamic engineer of J-8 and chief designer of J-8II, also participated in CJ-6) for more information but found little more than the above videos, so I think it's not necessary to post it right now. No specific answer but I think maybe about the manufacture. Gu remembered that the structure designer called him from the factory, that the trailing edge of NACA23013 (used at wing root) was too thin to process. Finally, they chose to cut off some area of the thin trailing edge. This problem showed their processing capability was quite limited at that time and might be related to the design.

[LowRider88]

3 hours ago, Torbernite said:

I'm also afraid that CJ-6 would not touch those more interested in combat mission. But the simpleness makes it possible as a mod, and this topic of trainer is more suitable as a mod. (I mean most lovers come for enthusiasm and preference while those who want an interesting combat aircraft may not buy it.) I think you may find someone willing to do that. Deka seems to have no spare productivity for another primary trainer into DCS. 

I checked the memoir from Gu Songfen (aerodynamic engineer of J-8 and chief designer of J-8II, also participated in CJ-6) for more information but found little more than the above videos, so I think it's not necessary to post it right now. No specific answer but I think maybe about the manufacture. Gu remembered that the structure designer called him from the factory, that the trailing edge of NACA23013 (used at wing root) was too thin to process. Finally, they chose to cut off some area of the thin trailing edge. This problem showed their processing capability was quite limited at that time and might be related to the design.

I am by no means suggesting that Deka detract their attention away from the J-8 to focus on this.  I am eagerly awaiting the availability of the 8.

I am just suggesting that if they were willing and able, Deka could potential deliver the CJ more easily since it has already been made available as a mod else where, and maybe with some partnering it could be an easy win.

I like that Deka takes their time to deliver a nearly completed project, rather than deliver it partially done.

However the side effect of that is waiting painfully from announcement time to delivery.

If they were willing and able, maybe a quick win in the mean time could give fans a little something, and help with the funding.

I disagree, I believe the CJ would sell well.  Motoadve says many people would be interested.  And there are already other trainers in DCS, like the CJ’s brethren the Yak.  The CJ also has the B, armed variant, so it could be used in combat.

Thanks for digging into the square tip question.  I find those details you got from the designer very fascinating.  From what you said the trailing edge was trimmed, but this to me doesn’t really explain the square tips, and further why there were square tips on the tail surfaces too.  But great info, Thanks for sharing!

[IvanK]

Hell yeah .... Here is mine M14PF powered.

6g Cv is 149Kts

Edited March 6, 2023 by IvanK

[PLAAF]

CJ-6 is cool. But I have a feeling that the next module of Deka will be the Q-5, which is to me at least, much more attractive than CJ-6. Especially if it is the L variant or anything equal to or later than the III variant.    Since all Q-5s are retired, so I doubt Deka will get any fatherly rebuke from the PLA when they ask them for permission to even make the latest Q-5L variant. 


 

[Naudiz]

2 hours ago, PLAAF said:

CJ-6 is cool. But I have a feeling that the next module of Deka will be the Q-5, which is to me at least, much more attractive than CJ-6. Especially if it is the L variant or anything equal to or later than the III variant.    Since all Q-5s are retired, so I doubt Deka will get any fatherly rebuke from the PLA when they ask them for permission to even make the latest Q-5L variant. 


 

Do you reckon that's possible? It seems to me that the domestic chinese hardware is what is preventing them from making a lot of the modules.

Uboats even stated it wasn't possible to do the simultaneous version of the J-8 that was developed from the J-8PP, even though they looked into it.