Queen Liz Carrier with Full F-35B compiment versus?

[sprstdlyscottsmn]

I forgot about the Skyray. Key differences in the wing itself is that the F4D has a much thicker wing and a much lower wing loading compared to the J-20. The F4D is a wing with a small cockpit at the front.

Yes the J-20 canards will be producing a lot of lift, but the main wing is so far aft (there is a lot of plane in front of the wing, the LERX won't help too much at low AoA). Looking at the J-20 in planform the wing sweep doesn't appear that drastic (compared to Skyray and Rafale), it's just so far aft. I just don't think that arrangement is well suited for carrier ops. I'll just wait and see if the Chinese prove me wrong.

[jessmo112]

Well it all started with J-20 doesn't have enough thrust to be able to take off from super carrier. So I explain why it isn't true but folks still try to prove it lack thrust only because WS-15 isn't ready. That is why I am focused on T/W ratio.

I agree that T/W ratio shouldn't be an issue or much of an issue regarding being able (or not) to operate from a carrier, namely from a "super carrier".
Any 'lack of T/W ratio' which the J-20 could have (or not) should 'only' impact its capability while being in the air and when performing missions (such as engaging enemy aircraft or not being able to carry heavier payloads for example) and again not directly in its ability to operate from carriers.

Size is problem but that is also exaggerated on early estimates of J-20 which back then was long 23m.

In fact J-20 is smaller then J-11.

So it is smaller then J-15 too.

The problem is that size or should I say the area that an aircraft occupies inside an aircraft carrier's hangar for example isn't dictated only by its length or even by it's wingspan. Wing area for example is also and probably a bigger issue when it comes to taking up space in an hangar. For instance a wing with a slightly smaller wingspan but with a considerably bigger wing area will occupy considerably more area than a wing with a slightly bigger wingspan but otherwise with a considerably smaller wing area and this applies even more to naval aircraft since they usually have folding wings which help to 'solve' the wingspan problem. Of course one can argue that folding wings also help with wing area but this isn't the same amount of 'help' compared with wingspan since the area or part of the wing that folds up is always a smaller area compared to the rest of the wing.
And this (wing area 'issue') is what happens with the J-20 compared to the J-11 and J-15. Take a look:

J-20 (land based aircraft):
length --> 20.4 m
wingspan --> 13.5 m
wing area --> 78 m2

J-11 (land based aircraft):
length --> 21.9 m
wingspan --> 14.7 m
wing area --> 52.84 m2

J-15 (carrier based aircraft):
length --> 21.9 m
wingspan --> 14.7 m
wing area --> 62.04 m2

So the Land Based J-20 despite having slightly smaller length and wingspan (1.5 meter less in length) it has a considerably bigger wing area (16 square meters more) compared to the J-15 which is a naval aircraft and then again the J-20 is a land based aircraft.
If we look at the figures above the J-15 which is basically a navalized J-11 has a quite big increase in its wing area (from 52.84 up to 62.04 square meters) and then I believe it's 'relatively easy' to imagine how much bigger the wing of a navalized J-20 would need to be compared to the land based J-20 and even more compared to the J-15 and how much more space a navalized J-20 would take up inside a carrier's hangar and on the deck compared for instance with the J-15 (and this just not to compare it with smaller fighter aircraft).

Im going to agree to disagree. I think weight is very much an issue. And when your plan for every launch is to use AB that says alot. AB only launches will effect.

1. The ship enviorment and safety. Hows the noise level I dont know, does the J-33 use AB for every launch?
The J-33 has had trouble taking off with a heavy load, why isnt the solution there AB.
If there is a problem with reheat or an engine failure then the plane could go off of the deck because its so heavy it only can launch with 2 engines in full AB.
Im not sure what the N number is but if the solution is to forget the N number and lets just rely on AB your going to have issues.

2. The life of the engine: like I mentioned before the engine has limited hours. Now your going to high stress them by making use AB every launch.

3. Recovery remember you need correct glide slope to get back on board, with snappy response, and full AB to get back Air born. There is no telling how heavy your going to have to make this thing in order to get the correct numbers at trap.

4. Fuel: Your going to burn alot of gas on take offs.

[jessmo112]

I wish we had some old carrier Dogs in here to tell us how much weight effects cat and trap.
If you were learning about your new plane, and the instructor told you, "this T/W this is the stall speed at sea level, but screw all that we will just use AB every cat".
What would you think.

[quicksilver]

Here ya go —

http://robertheffley.com/docs/HQs/NAVAIR_2002_71.pdf

[spazsinbad]

Thanks 'QS'. I guess some old dogs are puzzled by some things such as blather about A/Bs - neva needed one meself.

SEaRcHing dis forum for ROBERTtheFLY one can get other ideas about NAVAirV : robertheffley it's complicated eh.

Just one example: viewtopic.php?f=22&t=13450&p=219997&hilit=robertheffley#p219997

[sprstdlyscottsmn]

I wish we had some old carrier Dogs in here to tell us how much weight effects cat and trap.
If you were learning about your new plane, and the instructor told you, "this T/W this is the stall speed at sea level, but screw all that we will just use AB every cat".
What would you think.

T/W doesn't impact stall speed, think of it as purely weight based. FWIW the F-14A used Zone-3 AB on every cat shot and the F-14A+/B/D used Mil on every Cat shot. The F-35C seems to use Mil, the F/A-18A-D seems to use AB, the F/A-18E/F/G appear to be weight dependent. Point being, if the plane has an AB then for higher weights you can expect it will be used for cat shots. The F110 powered Tomcat was forbidden from AB cat shots due to the yaw moment in the event of engine failure exceeding the ability of the rudder to counter.

[marauder2048]

I forgot about the Skyray. Key differences in the wing itself is that the F4D has a much thicker wing and a much lower wing loading compared to the J-20. The F4D is a wing with a small cockpit at the front.

Yes the J-20 canards will be producing a lot of lift, but the main wing is so far aft (there is a lot of plane in front of the wing, the LERX won't help too much at low AoA). Looking at the J-20 in planform the wing sweep doesn't appear that drastic (compared to Skyray and Rafale), it's just so far aft. I just don't think that arrangement is well suited for carrier ops. I'll just wait and see if the Chinese prove me wrong.

The X-31 doesn't have closely coupled canards either but had no problems.
Not sure you can continue to ignore the utility of TVC in carrier approaches.

[jessmo112]

How would weight effect trap? Am I correct in assuming that the aircraft has to have a certain glide slope and air speed in final approach? Arnt all of these things affected by weight, engine power, wing area, ect?

[sprstdlyscottsmn]

The X-31 doesn't have closely coupled canards either but had no problems.
Not sure you can continue to ignore the utility of TVC in carrier approaches.

I was already writing my response when you posted yours so I didn't see it. Now that you mention it I do recall seeing something about that back in the day. I recall a diagram showing a very high AoA approach then the X-31 pitching down to land. Not sure I would be happy about that as a pilot. I would think the better implementation would be to have the canard in "pitch up" and have the TVC hold the tail up to allow for a slower approach speed. With modern FCS it could definitely be doable.

Not sure what you mean by "continue to ignore", I am not ignoring anything. There is a difference between "hadn't thought about that" or "I forgot about that" or "I didn't know about that" and "I'm going to ignore that."

[sprstdlyscottsmn]

How would weight effect trap? Am I correct in assuming that the aircraft has to have a certain glide slope and air speed in final approach? Arnt all of these things affected by weight, engine power, wing area, ect?

The aircraft has to have a certain glideslope and AoA, and the AoA is different for each aircraft. Airspeed for the approach is determined by what speed will put you on glidepath at approach AoA and is determined by the weight and the lift curve slope. A Classic Hornet has an approach speed between 130 and 140kt depending on weight.

[marauder2048]

With X-31 VECTOR, my view is that the J-20 planform + TVC is suitable for carrier approach.
Making DSIs resistant to hot gas ingestion, landing gear enhancements, spot-factor improvements
etc. are engineering challenges but none are insurmountable.

The only question is: do the solutions above impose such as cost (time, money, operational utility) so as
to reduce the attractiveness of the navalized J-20 relative to the J-31 or some signature reduction Su-33?

[spazsinbad]

Forgive me but what is this thread about please. I go by the thread title meself. It seems we have diverted to mythical aircraft and mythical super carriers. IF more is known about these beasts then something can be made of that detail.

And yet all we have is the past with LOTS OF DETAILS and EXPLANATIONS about how a carrier aircraft is made. These days seldom original design land based aircraft are made into carrier capable aircraft despite the PR and best efforts (Gripen?).

India has made a decent effort with their TEJAS-N but apparently will move on to a more specific naval design aircraft.

What has been posted is information about various aircraft designed specifically for naval aviation of various kinds. Because this is the F-35 sub section (geddit?) of the F-16-net forum there is a heap of info about the F-35C and F-35B.

Probably I have posted a PDF or six about 'how to design a carrier aircraft' OR how carrier aircraft are designed to the LIMITS OF THE AIRCRAFT CARRIER THEY INTEND TO operate from including the 'mythical' FORD class with EMALS & AAG.

So if more detail can be found about the catapult/arrest components of the mythical carriers of other countries then we can all sleep well in our beds tonight. China has a test facility for both steam & electro-magnetic catapults. India has facilities like other naval aviation countries to test their aircraft and the aforesaid equipment. Blathering on about vague stuff does not cut it in NavAv. YOUSE A GOTTA ROCK 'nROLL baby. Witness lots of detail about VX-23 crash & bash.

I could go on however there are lots of clues about designing an aircraft to fit limits of the intended carrier in the oft quoted but never read short tome about the F-35B/C being designed/modified for such purposes. Shake Rattle & Roll.

The Influence of Ship Configuration on the Design of the Joint Strike Fighter 26-27 Feb 2002 Mr. Eric S. Ryberg
http://www.dtic.mil/cgi-bin/GetTRDoc?Lo ... =ADA399988 (1Mb)

CARRIER SUITABILITY OF LAND-BASED AIRCRAFT 2012 HERNANDO, JL & MARTÍNEZ-VAL, R
http://www.icas.org/ICAS_ARCHIVE/ICAS20 ... RS/167.PDF (1Mb)

Flying Beyond the Stall [The X-31 “Goes to Sea”] by Douglas A. Joyce
https://www.docdroid.net/wVJKKd1/flying ... -stall.pdf (10.7Mb)

[sprstdlyscottsmn]

With X-31 VECTOR, my view is that the J-20 planform + TVC is suitable for carrier approach.
Making DSIs resistant to hot gas ingestion, landing gear enhancements, spot-factor improvements
etc. are engineering challenges but none are insurmountable.

The only question is: do the solutions above impose such as cost (time, money, operational utility) so as
to reduce the attractiveness of the navalized J-20 relative to the J-31 or some signature reduction Su-33?

Of the options of J-20N, J-31N, or Su-33SR I think the J-20N would be the least risk. Even the "impressively low RCS" (as some coworkers have said) of the Su-34 is still a bit more than an order of magnitude higher than the J-20.

[sprstdlyscottsmn]

Flying Beyond the Stall [The X-31 “Goes to Sea”] by Douglas A. Joyce
https://www.docdroid.net/wVJKKd1/flying ... -stall.pdf (10.7Mb)

Man that was a good read, even just going through the "Goes to Sea" chapter. Thanks Spaz!

[Corsair1963]

With X-31 VECTOR, my view is that the J-20 planform + TVC is suitable for carrier approach.
Making DSIs resistant to hot gas ingestion, landing gear enhancements, spot-factor improvements
etc. are engineering challenges but none are insurmountable.

The only question is: do the solutions above impose such as cost (time, money, operational utility) so as
to reduce the attractiveness of the navalized J-20 relative to the J-31 or some signature reduction Su-33?

Of the options of J-20N, J-31N, or Su-33SR I think the J-20N would be the least risk. Even the "impressively low RCS" (as some coworkers have said) of the Su-34 is still a bit more than an order of magnitude higher than the J-20.

Clearly, the J-31 is going to be the PLAN next Naval Fighter. So, why we keep talking about the J-20 is beyond me???


Plus, you must be kidding about the Su-34 having an "impressively low RCS". Was that a joke that I missed???