MKI is more heavy than MKK as MKK OEW is 17.7tonnes while MKI's OEW is 18.4 tonnes, thus normal take-off weight of MKI is more. Fomin didn't get anything wrong. 38+ tonne max take-off weight was also given for MKI later, but initially it was the chief selling point for more strike-oriented MKK variant.
MKI is the closest relative of erstwhile Su-35(T-10M) program(Su-35UB was literally KNAAPO's MKI variant), thus its specs like fuel-load, radar etc. are very similar. Because MKI uses normal Su-27UB tail-fins, it doesn't have 135kgs x 2 tail-fuel tanks, rest its wing and fuselage fuel tanks are "exactly" like like Su-35(T-10M) so it has 10250 - 270 = 9980 kgs of fuel. It's that simple. If you don't want to accept it then no problem. Just agree to disgree
No wonder you are so thoroughly confused. Su-27M and Su-30MKI have nothing to do with each other. Su-27M was a TD for canards, like Su-37 was for TVC. Su-30MKI was a derivative of the standard Su-27UB, ie, the Su-30M, and they added canards and TVC to it. It was completely independent from Su-27M and Su-37.
Su-27M was a single-seat jet which used a different fuel tank design derived from Su-27, and it cannot be used on the Su-30M family. There are significant changes to how the first tank was designed to incorporate the second cockpit and larger spine, to the point where the tank lost 800+ kg of fuel, and was compensated by redesigning some of the fuel tanks.
Only the single-seat got significant fuel upgrades. So Su-27 came with 9.4T, Su-27M came with 10.25T, and Su-35S came with 11.5T. Only the Su-27 doesn't come with tailfin tanks.
As for Su-27UB/Su-30, it came with 9.4T, redesigned forward tank. Su-30M came with more optimised 9.64T of fuel. Su-30MKI stayed the same and Su30MKK came with tailfin tanks to climb up by 270 kg. That's about it. There has been no changes to the fuel layout of the Su-30 since the M version. Even Su-30SM comes with 9.64T, proof that there have been no changes to the MKI.
Su-27M came with fuel tank design optimizations and tailfin tanks to increase volume while Su-35S eliminated the air brakes for an extra tank. So you confused the fuel tank capacities of the single-seat with the twin-seat.
As I said, none of the twin-seat jets exceed 10T of fuel.
Su-35UB was KNAAPO's offer to China for an MKI-competitor, all with the same stuff like Bars and AL-31FP. Little did the Russians know at the time, the Chinese were already on their way to create the J-11B. Su-35UB was derived from the MKK's airframe and modified with canards and TVC the same way as the MKI, it had nothing to do with Irkut's MKI design. Later KNAAPO remodified the Su-35UB back into the standard MKK for display.
Look you can claim agree to disagree when we are both speculating. But you can't claim that when you get your facts completely wrong. It's meant for opinions.
I have already posted the Su-30MKM life-extension declassified report and you already know about it. Even after pulling in numerous near 13G maneuvers, the core titanium structure of MKM hardly showed any fatigue. Real life of MKI's airframe is way more than 6000hrs quoted figure by the OEM.
So, as I said, 18.4 tonnes in the worse case and sub 18 tonnes in the best possible case for the UPG. variant with 135-140KN of uprated thrust from our indigenously uprated & upgraded AL-31FPs(or in future 177S/117S), providing MKI UPG. with lots more electrical power and thrust-to-weight ratio along with much better TBO and overall engine-life.
Since you don't wanna accept the above then just agree to disagree
The IAF seems to want to extract about 12000 hours, that's the point of life extension. What you saw on the F-16 is how it's done. Richer air forces generally try to avoid it, hence they stick to 30-year life compared to our 50 years.
I never said anything about AL-31FP not being upgraded or even replaced after Phase 2. In fact, that's my position, as I said, to compensate for the weight increase. If you are wondering about Midhani's new materials, as I said, it's possible on the MLU, but not on the currently produced AL-31FPs, the order for 240 engines, where deliveries began before certification of the new materials. The standard AL-31FP can be uprated with Russian parts too.
The MKM paper you read was just after 10 years of service (2008 to 2017) and the aircraft was supposed to go in for overhaul. But here we are talking about end of life, ie, 25 years. MKM's opportunity for that is still in the 2030s, if they are matching our hours. You are comparing overhaul to life extension. This is not an opinion either.
At 240 hours a year, our jets are going through 3 overhauls at an interval of 6.25 years each, so the life extension seems to be happening in the 25th year, followed by 3 more overhauls, for a total of 11000-12000 hours, ie, around 23 years. So 48 years in total.
