For the final time.......WHO SAID it was 13,300? Whoever said that has to prove it, BRF is not meant for people to start wild goose chases.
It was BR. I clearly remember the 13300 fig in BR. After searching in vain, I finally got to the source BR/BRF.
The specs have been removed but here are a few forums which displays BR's MKI specs:
http://www.echarcha.com/forum/showthread.php?t=9166
http://forum.keypublishing.co.uk/archiv ... 31898.html
I see a George J there, is that you?
Krish, you are right - it is virtually impossible to find the infoboard with 13.3kgf AB thrust for AL-31FP. I feel your pain. At least I have not found said inforboard despite multiple searches. Rest assured though, the thrust is definitely higher than the what is seen in most open sources. It stands to reason; also there is have been noises about this from a few sources:
eg. The phil camp/watson book on the flanker in IAF service does mention the need for a higher thrust engine (compared to the older ones of course) for the structurally beefed up MKI.
FWIW, here is one source that dates around from way back but puts the engine thrust @ ~ 13 tons, btw they get their info from Fomin (2000) i think
Thanks much Cain.

So later they went back to the 12.5 t thrust later on. Was the earlier fig a mistake or is it trying to heed IAF's request to not publish the actual thrust. So BR got that figure from Fomin/Milivia and used that fig in their site? I saw BR with 13300 many years ago and the forum links posts are old, so did BR update their site with the 12,500 fig later on? So many questions. But I think I'll stick with 12.5t for now.
The difference between the MKK and MKI is v.clear. The MKK is as heavy (probly heavier considering the MKI has slowly been incorporating composites, 6% by weight iirc), but uses the regular AL-31Fs @ 12250kgN. The MKI is @ 13000KgN.
Also keep in mind KN > KgF even if only marginally, which would put the Al-31F at the oft published 12500kgf and the MKI's AL-31FP @ 13300kgf. Resident experts can explain the difference far better i am sure.
No... 130kn would be 29,225lbf
29225 < 13300(29321) ~ 29400
Yeah, but MKI puts on a lot of weight than MKK in additional avionics, heavier radar(?), canards, thrust vectoring, strengthening for Brahmos. 6% isn't much to cover for all that weight. BTW, by what factor does Russian/our composites reduce weight?
see you dont need to use a translator, they do have an English site...you just need to look
You could see the numbers. But I had to navigate to that page you know.
It's strange that
http://www.npo-saturn.ru page displays the Al-31 page if visited the second/third time. But the same page displays another page if you clear the cache/cookies or use a different browser and access it the first time. Weird. Or is it my browser which is at fault.
If these pics convey the same info then its 12,700 if not then we are back to 12,500 coz NPO and HAL say the same and IAF does not know the difference between 5 and 7.
It could be that Al-31f/fp can be said as a 28k lbf Class engine(27600 ~ 28k class, or a number with a 1000 multiple). 28000lbf =
12700.72 kgf ... accurate to the last digit excluding decimals.
I had taken this photo in Aero India 2005. Check out the board where it says the thrust is 12700 KGs each
Thanks Ravi!
