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MrCrazyBoyRavi

New Member
Registered Member
just a noob question. I have heard that in a conflict in Tibet, Indian aircraft can take off with much more fuel and higher payload, while Chinese aircraft taking off from higher altitude will have difficulty carrying much payload. and in some cases some aircraft need to fly from inland and refuel in mid air to carry equivalent payload to Indian aircrafts. What's the science behind it?
 

lcloo

Junior Member
just a noob question. I have heard that in a conflict in Tibet, Indian aircraft can take off with much more fuel and higher payload, while Chinese aircraft taking off from higher altitude will have difficulty carrying much payload. and in some cases some aircraft need to fly from inland and refuel in mid air to carry equivalent payload to Indian aircrafts. What's the science behind it?
Basically it is about oxygen level, take off speed and length of runway.

Less oxygen on high altitude means engines cannot burn efficiently while on the ground at taxi speed, result in lower acceleration and thus will not be able to achieve take-off speed with heavy load if the runway is not long enough. Simple solution is to build longer runway, e.g. instead of 1,000 metre runway. a 4,000 metre runway is built.

Also, thinner air flowing above the wings at take off speed, created less efficient lifting effect.
 
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Air Force Brat

Brigadier
Staff member
Super Moderator
In my opinion, the J-10 is the best aircraft in China's military industrial history, it's much more important than the J-20. Versatile, cheap, easy to maintain, high combat performance, this is a great aircraft. There are many who think that J-20 is better than J-10 because of its invisibility, but don't forget the F-117 lesson. J-20 and J-10 are like Tiger with T-34. It would be even better, if China developed a special version of the J-10, similar to the F-35B role, operating on aircraft carriers.
Thank you for sharing your opinion, you wisely point out some the J-10's strong suits, and I agree with you it is a great aircraft. #1 the J-20 is not invisible, with proper optics you could likely see the J-20 at 50 kilometers. It is L/O, or low observable, with shaping and coatings designed to reduce its radar reflectivity, and in the case of the F-35 and F-22 nozzles and structure to reduce the heat signature that would be visible out to around 50 kilometers or a little better on your IRST, as a result the J-20, F-22, and F-35 have much reduced radar and IRST signatures, they have lot of other advantages,,, but lets stop there.

Now you encourage us to "remember the F-117 lesson", the F-117 proved very, very effective at striking targets in heavily fortified anti aircraft environments, however due to the F-117 following the same track in, night after night, so after putting all the pieces of the puzzle together an F-117 was indeed shot down during the "Balkan Conflict", pilot ejected and was rescued, ONE F-117 was lost out of all the actual combat missions it ever flew, a LOT of combat missions..

Finally and back on topic, you wish that Chengdu would build a STOVL version of the J-10, comparable to the F-35B to operate off their carriers, I'm assuming you are talking about CV-16 and CV-17? and that would indeed be awesome, but a very complex problem, particularly if you choose to equip the "J-10B" with a lift fan such as the F-35 uses for most of its vertical lift thrust, for starter all STOVL aircraft to date have a mid-mounted main wing rather than the aft mounted delta of the J-10.

So yes the J-10 is a very effective fighter aircraft, in fact if I'm not mistaken? the main flight demo team in China uses the J-10 as its high end bird for aerial displays, but I'm going to seriously object to your assertion that the J-10 is a better airplane than the J-20...

I'm gonna take a leap of faith here and imagine that nobody who might meet the J-10 in a mano-a-mano aerial combat is sweating bullets every moment of every flight, but somebody who might indeed encounter a J-20?? he's concerned, he's thinking about it, he's doing his DACT training and taking every opportunity to "game it out", and put together a plan that might help him emerge victorious or at least be able to "bug out".
 

Air Force Brat

Brigadier
Staff member
Super Moderator
Basically it is about oxygen level, take off speed and length of runway.

Less oxygen on high altitude means engines cannot burn efficiently while on the ground at taxi speed, result in lower acceleration and thus will not be able to achieve take-off speed with heavy load if the runway is not long enough. Simple solution is to build longer runway, e.g. instead of 1,000 metre runway. a 4,000 metre runway is built.

Basically less oxygen means you cannot use as much fuel since it won't burn efficiently, so you have to reduce the amount of fuel since you don't have enough oxygen to make the much higher thrust you would get at sea level.....


Also, thinner air flowing above the wings at take off speed, created less efficient lifting effect.

actually, Thinner air requires much more airspeed to build up the pressure "under" the wing to create the lift needed to lift your airframe, the same with rotary wing aircraft, every wing is less efficient in thinner air. Wings are shaped in such a manner that as you accelerate the air pressure under the wing rises, as speed increases eventually the wing builds enough lift to fly...
 

Air Force Brat

Brigadier
Staff member
Super Moderator
In my opinion, the J-10 is the best aircraft in China's military industrial history, it's much more important than the J-20. Versatile, cheap, easy to maintain, high combat performance, this is a great aircraft. There are many who think that J-20 is better than J-10 because of its invisibility, but don't forget the F-117 lesson. J-20 and J-10 are like Tiger with T-34. It would be even better, if China developed a special version of the J-10, similar to the F-35B role, operating on aircraft carriers.
We also have a new members thread were you may introduce yourself and tell us a little bit about your interests, work, family if you wish, welcome aboard, you will find this a great bunch of guys, feel free to pm me when you've made at least 10 posts.. We want to encourage you to read the rules, be cool and make some very cool friends, the mods are all nice guys except for ME, sorry, I am a Brat.
 

SinoSoldier

Colonel
Basically it is about oxygen level, take off speed and length of runway.

Less oxygen on high altitude means engines cannot burn efficiently while on the ground at taxi speed, result in lower acceleration and thus will not be able to achieve take-off speed with heavy load if the runway is not long enough. Simple solution is to build longer runway, e.g. instead of 1,000 metre runway. a 4,000 metre runway is built.

Also, thinner air flowing above the wings at take off speed, created less efficient lifting effect.
Could this technically be solved by using engines with more compressor stages? Not that it would be realistic to actually do this, but as food for thought?
 

Air Force Brat

Brigadier
Staff member
Super Moderator
Could this technically be solved by using engines with more compressor stages? Not that it would be realistic to actually do this, but as food for thought?
I could indeed help, but it would also increase weight, with a recip you could add a turbo or supercharger, which would also add weight.

Its always helpful to remember that the aerodynamic issues could be improved by a larger, high aspect ratio wing, but that would also increase weight, negating many of the benefits of each of these modifications.

Density altitude goes up with the temperature increase, and down as the temperature decreases, lot of airplanes have been put into the trees on hot days, lol.
 

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