An interesting but flawed article on the J-20’s bay doors:

http://defensetech.org/2011/09/02/j-20-stealth-fighter-doors-explained/

J-20 Stealth Fighter Doors Explained

This Friday morning — more like midday — is going to be devoted to stealth jets here at DT. Look at the above picture of China’s J-20 Stealth jet. See that big open door just forward of the main landing gear? My colleague Phil Ewing recently asked me if it’s the opening for another weapons or equipment bay.

While I’m no expert on this fighter, I think we can say that we’re seeing the main landing gear bay. Look at the photos below and notice how the gear should fold forward into that open bay.

Chalk any confusement up to grainy pictures of the plane combined with the layout of the forward-folding landing gear and the placement of the bay door. Keep in mind that the door could also provide maintainers access to other internal systems on the plane in addition to accommodating the landing gear.

You can see in the last photo below how that open gear door looks like it wasn’t meant for the landing gear.

The real mystery surrounding the giant plane is; what will it be used for?

My guess is that it’s a high-speed interceptor along the lines of the famous MiG-25 Foxbat and MiG-31 Foxhound or that it’s meant to be a penetrating, F-111 or F-15E-style weapons truck designed to strike heavily defended targets like air bases or carrier battle groups. As you can see in this video, it certainly appears to have the weapons carrying capacity for either of these missions.

Just in case anyone here who might know better is enticed into believing this, I want to say their speculation on the plane’s role is utter cow’s manure.

If J-20 was a striker we wouldn’t be seeing J-20’s configuration as it is now — i.e: no canards, and likely no all moving tails either. The weapon bays would also likely be a different configuration. Also, there’s years of speculation and credible rumours and even a PLAAF deputy air chief’s backing to give us knowledge about what this plane is meant to be. That J-XX/J-20 is a stealthy, supercruising high performance air superiority fighter primarily.
Also, think about the logic. Why would PLAAF go for a high speed interceptor? What super high speed aircraft are there which its enemies operate which would necessitate a dedicated stealthy interceptor? Why couldn’t you create a manouverable fighter capable of high speeds as well?
On the flipside, what need does PLAAF have for deep penetrating strikers? Which heavily defended IADS are there near its borders which land based SRBMs, LACMs and conventional strike aircraft cannot hit? As for an anti carrier mission — would it be logical to send a dedicated aircraft out to face a CVBG and delivering an arguably limited payload (let’s say two YJ-82s a pop — and that’s ridiculously overestimating the size of J-20s weapon bays) and coming into range of aegis, advanced hawkeye, and CAP? Even if J-20 had the speed and altitude to escape, why risk such expensive purpose built assets when you’re hitting one of the enemies arguably strongest points? Why not say, use a long range ballistic missile to test the less proven ABM shielding of naval craft instead? Or even quiet SSKs laying in wait? Or how about dozens of small stealthy FACs waiting in the littorals? -hint hint-

So basically there is no reason for PLAAF to go for a dedicated striker, or interceptor — though J-20 will be able to perform similar roles along the lines of how F-22 does, only probably with greater range and endurance.
If this plane isn’t a striker or interceptor, then what is it? Well the first answer always should have been — an air dominance aircraft.

But why would people think otherwise? A few reasons. One is that the wings look a bit small for the plane (debatable, I think they seem quite well sized). Another is its perceived large size. But even then there’s no reason a big aircraft cannot be manouverable (flanker anyone?).
But perhaps a powerful reason, is this, as illustrated by a commentor on the article through the link:

China knows it can’t match us on a level playing field so they design a long range stealth aircraft with the sole purpose of destroying our critical assets, therefore circumventing a head-to-head engagement.

I’m sure you can think up a level headed response.

Rant/post over. Hopefully I’ve convinced anyone who still thinks this aircraft is a dedicated striker or interceptor otherwise 🙂

Even at 21 m, it’s a big aircraft because of its configuration. Of the aircraft we tend to compare it to, the Su-27 is long because of the way that the area distribution is managed – with a long body in front and engine nacelles to the rear – and because of the tail sting, while the F-22 has booms and tails hanging way out the back.

Roughly speaking, the J-20 has a similar body cross-section to the F-22, but where it counts – nose to exhaust – it is a lot longer.

+1, J-20s definitely got a lot more space where it counts compared to F-22.

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@starikki, nice one that definitely does change things a little.

No clearly J-20 is under 22m, we’ve got an insider saying it’s 20.3m, our own analyses compared with a fixed variable gives it around 20.5m. This aircraft is not that big, eyeballing won’t be changing the maths.

Once we get to 2017 you might have to change your mind on J-20s final configuration 🙂

Posted by eagle over on CDF…

hrrrggggg — so this picture, and the other two I posted a while ago are said to not be of J-19 but “JH-7B”… Hmm

EDIT: hrrgggg, nvm it’s of the KFX, false alarm 🙂
http://bemil.chosun.com/nbrd/gallery/view.html?b_bbs_id=10044&num=92441

second point is larger fuel tanks of larger aircraft. large size aircraft like Su-24/Su-34. Even 40 aircraft in total can bring down a third world country in couple of days. You dont need 6 months for that.

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China lacks both large loitering aircraft and high speed bombers. so it will not be able to react to tactical long range situation.

Well if you consider 40 Su-34s to be a potent force, China does have 100 MKKs/MK2s and a further 190+ JH-7As, which despite what you may hear is more comparable to a Tornado than Jaguar and certainly has the range, while lacking the self defense of F-15E or flanker derivatives.

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@TR1, agreed

🙂
Here is a blurred out and intentionally censored image of a desk-top model of that particular SAC 601 4th (5th) Generation J-XX concept – as seen in the drawing posted by Blitzo et al. Rumor has it that SAC 601 offered two different concepts – the J-19 and the J-21 – the J-21 is the concept with the twin V-tail, like that on the American YF-23. The J-19 concept looked more like the YF-22 / F-22. But of course Chengdu CAC 611 won the competion for the contest with their J-20 – that we all now can see. But SAC 601 might still be pursuing their efforts with advanced combat aircraft – giving the Chinese PLAAF more options. Just like the open competion between the L-15 and the JL-9 series for an advanced supersonic trainer.

Interesting picture — but I do not think J-20 and SAC’s 4th gen will enter a competition like JL-9 and L-15, PLAAF already seem commited to J-20 and SAC’s plane might be a supplement like a heavy striker or form the low of a hi-low combo (costing less due to less advanced avionics compared with J-20)

Good post!

That many J-7?? Still!?! Are all of those actually regularly flying/airworthy?
I think they would do well to gut that number considerably.

Most of those J-7s are still pretty new; E and G variants (remember CAC was still producing these things in the 2000s — they’ve come a long way to J-20), so they’re definitely flyable and not unuseful if flown well.
But I think their airframes don’t last very long so expect a lot of them to be replaced in coming years as J-10 production ramps up.

looks like PLAAF appreciate the value of range in Pacific, unlike Some other airforces…

ok my last snicker at DoD for a while now.

Bill Sweetman has a point you know, F35 faces block obsolescent when facing oppositions like T-50 and J-20, and even F-22 is at best evenly matched. there is no dominance anymore thus put USAF in an uncomfortable position of using shear numbers, once again.

Time to restart a bid for 6th Gen fighter (GO Boeing!) and meanwhile dust off F-22 line and re hash a F/B-22 out of it. go for speed, range and firepower, forget maneuverability.

I’m sure the US will have fun finding the money to fund NGAD, not to mention NGB… let alone a F-22 striker lol…
And I won’t say USAF is in an uncomfortable position, only they’re due to be in a slightly less overpowering one than a few years ago. Let’s see how J-20 and T-50 procurement goes and what USAF/USN brings to the table beyond F-35 (how long that will take will be important).

I’ll be interested in how SACs 5th gen influences things. While we can’t be sure PLAAF will buy loads of them, the potential appearance of a second stealth fighter from one country within more or less a year is sure to spook DoD.
And PLAAF could use a stealthy multirole striker to supplement J-20’s airdom in future. That would be a nice watershed moment — the world’s first heavyweight 5th gen striker.

It took Blitzo and you, what, 4-5 posts back and forth to get the joke.

you are seriously too serious.

lighten up. you came here for enjoyment.

Just for the record I got the joke when you said it :p

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(“you are seriously too serious” — classic)