negi wrote:Rakesh I was merely pointing at the fact that we need force our own narrative and at times it is the right thing to resort to "ashwathama hatha iti narova kunjara" (Yes Aswathhama is dead ;I don’t know if its a man or an Elephant.) i.e. to turn the other way when facts come in the way of forming a narrative which suits our interests . A lot what India does or will do will be dubbed as 'xyz' copy or derivative facts be damned and hence my first post nothing more nothing less.
I am not much concerned about Gripen they won't win they neither have the platform nor the financial muscle power to bribe their way through the others are much powerful in both departments.
This isn't about any "Narrative" but about technical design configurations arrived to and solidied into formal funding proposals years before any interaction with YAK ever took place (in fact during the Cold War).
This claim (earlier one regarding the two) does not hold up to the accuracy test. There is only one thing that the two aircraft mentioned by you share in common and that is the Nozzle, a Nozzle that on the JSF is designed by P&W (For both its engine and the now cancelled GE F-136) based on it's own 3BSN designs that it tested in the 1960s including demonstrating to their airframe contractor, and the US-Navy vectored thrust for the purpose supplying vertical lift. As I have shown in the US thread, this propulsion design element was selected by Lockheed to be included in its propulsion system, and was pitched to DARPA based on which money was allotted to them to begin hardware demonstrations even prior to them reaching out to YAK design team.
So again, what exactly was copied? There is actually a better case to claim that YAK-141 was based on a lot of concepts proposed for the Convair Model 200 that also use a similar 3 engine set up (two in the front, one in the rear) and vectored the thrust by 90 degrees in the rear. In fact the similarly is even more striking and we know that on the Convair, both the front lift engine and the nozzle were tested more than a decade before YAK built their system. But that is besides the point..The Convair 200 only designed and tested some key propulsion components using this design...whereas YAK built it and flew it.
Similarly, one can claim that the MCD approach was based in principle to what the YAK team and Convair's team proposed in the 1960/70s and 1980s with some modification (one big lift engine in the front as opposed to two smaller ones). But the Lockheed approach is fundamentally different. So the claim that YAK-141 and F-35B offer similar propulsion concepts is ok if all one does is look at two photos and take an eyeball approach but it really does not pass the accuracy test at a technical level..
In Summary -
1. Convair's Approach on the Model-200 - 2 x Lift Engines in the front and a 3BSN equipped main engine in the rear that swiveled 90 degrees to provide additional lift. <---- This was designed (But full up vehicle never built) in the late 1960's based on components (Front engines and Nozzle for the rear) designed and tested in the mid to late 1960's and early 1970s.
2. YAK's Approach 2 x Lift Engines in the front and a 3BSN equipped main engine in the rear that swiveled 90 degrees to provide additional lift. < ---- This in the late 70's to 1980s.
3. Lockheed's Approach 1 High thrust engine in the rear equipped with a 3BSN that swivels 90 degrees to provide additional lift + A clutch mechanism that engages a lift fan up front (lift fan does not equal to an engine for obvious reasons) and provided power to it from the main engine in the rear.
I can understand if someone claims
1 and
2 are similar (or damn near identical design decisions) and if one was based on their review or both design teams arrived to a similar configuration through an independent trade analysis. What I do not understand is how 1 and 3 or 2 and 3 can be called copies of each other. They are fundamentally different. One would have understood the "influence" bit if Lockheed went to YAK and said,
"we really like what you did with the Nozzle, could you please give us rights to use it". But they did not do this. They partnered with P&W and asked it to use the design (modified) that it had patented for Convair and the Model 200. So much was their risk aversion that they did not want GE to design, develop and bench test a competitive nozzle design for the F-136. They wanted no additional risk when it came to demonstrating the STOVL capability with both the GE F136 and PW F135 design proposals. They wanted one unified, de-risked 3BSN configuration that was based largely on the design PW physically tested in the 1960s.
They went to YAK for one thing - Getting them to test, repeat, test, repeat and provide results to submit along with their submission that showed reliability and the fact that the concept would be able to compete on these metrics when pitted against much less riskier nozzles proposed by their competitor. I attended Dr. Bevilaqua's lecture when he gave a similar one (to the one in the video on the US thread) at Johns Hopkins APL and someone asked him later during the meet and greet whether they had access to all of Convair's testing and analysis. His answers NO. They only had limited data that Pratt held rights to. The other data was actually controlled by their main competitor - Boeing.
