From the Su-30 thread -
when did Yak-38 started flying(1st flight 1971) and when did Yak-141 started flying (1st flight 1987) and now see when did F-35 start flying (1st flight dec 2006)
The 3BSD was something the creator had patented with US Government money years earlier to the first flight of the YAK or even before it was revealed. The Convair 200 was designed for this very purpose and multiple vendors within the US DOD industrial base were given contracts for a three bearing swivel nozzle.
Yak-38 Forger had two smaller lift/ cruise engines and the lift fans. The data and design inputs for Lift fans came from here
The Convair design of the early 70's ( developed in the late 60's) had two 10000 pound lift engines behind the cockpit and a single JTF22A-30A developed by Pratt and Whitney equipped with a Pratt and whitney patented 3BSN that turned down 90 degrees. The propulsion architecture was studies on a test bed and testing data gathered and evaluated in the 60's.
By the late 1960s, Pratt & Whitney was designing and testing a three-bearing swivel nozzle for use on the Convair Model 200 Sea Control fighter. Design drawings dated 1967 show detail design layouts. The first nozzle was built and tested on a Pratt & Whitney JT8D in the mid 1960s. The tests included operating the nozzle in full afterburner with the nozzle deflected ninety degrees. The test rig was positioned to exhaust upward to avoid heating the ground under the test stand, though subsequent tests positioned the nozzle downward at the ground to assess the effects of ground proximity back pressure on nozzle performance.
Pratt and Whitney secured patents for the 3BSN that they designed for the above mentioned project. I am yet to see a russian design patent on the 3BSN that predates this design.
Now coming to the lift fan which you say lockheed took from YAK -
The XJ99 was a product developed by the Allison company for the Convair 200. It was developed, extensively tested and given an evaluation. Two of these lift engines were to be positioned right behind the cockpit of the Convair 200 in the 70's. The engine was reported on the various aviation publications all through the 70's. Here is one such report -
http://www.flightglobal.com/FlightPDFAr ... 201422.PDF
What followed in the early days of the F-35 competition was a rebalancing of the US defense industry in ancicipation of the upcoming contract award and the standard rejig as national defense outlook changed. Lockheed began absorbing General dynamics and its Texas business which it inherited. Boeing bought McDonnell douglass that had purchased convair and general dynamics california based business and design IP. From the shake up, boeing had more data on them than Lockheed (this was convair's IP passed through to General dynamics and then spread out towards lockheed and boeing). Interestingly a company that was closely behind Lockheed and BAE systems (Lockheed partner eventually) -
ROLLS ROYCE quietly acquired ALLISON which in the 60's had developed the XJ-99 and had extensive testing data on it along with other lift fan concepts This combination of companies lead to a successful porting of the JSF STOVL (Lockheed's version) over to the 3BSN and a lift fan design which had been studied quite extensively (Including hardware testing, lab testing and filing patents after extensive research) by Pratt and Whitney, Lockheed (through convair), Rolls Royce (Through Allison). The 3BSN design along with a lift fan architecture were frozen way before lockheed went to russia to use YAK as a consultant to peer review their designs.
Yak-38 Forger had two smaller lift/ cruise engines and the lift fans. The data and design inputs for Lift fans came from here
Not quite true. The Lift fan coupled with a 3BSD design had been studied by the USN year prior to the F-35 in the 1960's and early 70's. Lockheed Martin narrowed down on the 3BSD design when they got money for the ASTOVL. Now read this carefully - After selecting the 3BSD design they chose to add Yak as a consultant to de-risk it since Boeing was not going to help much (They were competing with lockheed for the largest contract for fighters in the world). That was the scope of YAK's involvement. YAK didn't help then narrow down on a 3BSD, something that had already been verified on a engine tested through extensive testing by Pratt decades earlier and even years earlier to the Yak-38 first flight.
Risk reduction done around 95 and LM took 11 years to mitigate risk. Had it been risk reduction then 11 to reduce risk is Awesome!!!
It did not take 11 years to mitigate risk. Try to develop some basic understanding. They met with YAK in the 90's and then submitted their design along with the X-35 proposal. The design for the 3BSN remain unchanged from the time before they went to YAK and when they concluded their business with YAK. The X-35 plans were presented to the soon thereafter and the demo program for the 3 versions of the X-35 started 5 years later. The contract to locked was awarded in 2001 or 2002 and then the SDD (Systems development) phase of the program started. The time it takes to get a production representative aircraft from X35 to F-35 is there, not because lockheed was busy learning lessons from YAK but because the US development programs begin the critical design review processes only after the downselect has been made. Basically, lockheed designs its own aircraft for the prototype to the best of its ability. Once the SDD phase begins the 3 services join hands, develop a Joint program office and there is active involvement at every step between the USN, USAF, and USMC as the systems of the jet develops. The systems for the F-35 were very extensive. They involved a weapons bay (which did not exist on the prototype), the entire systems architecture, aerodynamic changes and solving the weight creep that comes with all this. The 11 years between the events has absolutely nothing to do with YAK but with the critical design review process and solving the weight creep issues that had come up due to the added burden of the system, sub systems, avionics, newer materials and a weapons bay. Try to read on some basic stuff of what goes on at what stage.
Had it been risk reduction then 11 to reduce risk is Awesome!!!
What is done during the SDD phase is not risk reduction. Lockheed COULD NOT go back on their plans submitted based on which they have been evaluated. RISK REDUCTION is done only for the submission. Once the program is downselected as the winner it is assumed that the level of risk is acceptable. No one reduces the risk in systems development - those efforts are made before the time of submitting the bid.
What lockheed did in the SDD phase was turn the X-35 into the F-35 i.e a production representative multi role fighter, with a full avionics architecture, all the systems, all the sub systems , full production standard engines in place of converted F-119's on the X-35, a weapons bay with the required weapons capacity and bring aboard the new RAM materials it had proposed for the program but not used on the X-35 prototype for obvious reasons. All that takes time as it did with the YF-22 to F-22 transition which was much simpler due to 1/2 the integration code, one model, limited initial multi-role capability scope and the fact that the YF-22 was a more complete prototype than the F-35 (Had weapons bays, flew with sensor prototypes etc).
The STOVL architecture of the F-35 was frozen at the time lockheed submitted the design bid for the JSF many years earlier based on 100% their own research that involved their own investment and using money invested by the US DOD on technical research conducted in the 60's and 70's through United technologies and others (Allison, general dynamics etc). There was a delay on the B version of the jet because the critical design review process was delayed because the weight creep on the aircraft exceeded the models that were acceptable for the USMC (SDD phase has equal service and vendor involvement). A two pronged approach was created to lower the weight and increase the thrust and this took some time and extra cost.
Reference Book - "Lockheed Martin"
- By Relly Victoria Petrescu, Florian Ion Petrescu
Page 86-Last-Para
"The STVOL version of both power plants use the Rolls-Royce LiftSystem, designed by Lockheed-Martin and developed to production by Rolls-Royce. This system is more like Yak-141 and German VJ 101D/E than the preceding generation of STOVL design
And what this fails to mention is that the preceding generation of STOVL was the harrier but only because it was operational. Any article or research paper that is ever written (comprehensive) on the F-35B will mention the AVS program, the 3BSN patented by United technologies and the various programs that lead to the current propulsion architecture (AVS, ASTOVL, CALF, SSF and JAST) . Designs had been studied, extensively worked out through study contracts both towards the aircraft makers and propulsion providers for other STOVL efforts which used a 3BSN for applications such as the Convair 200. Read up on the Advanced Vertical Strike program that was lead by the USN in th 1960's and that developed concepts, verified submissions and allowed the OEM to conduct extensive research and safeguard that through their patents. Why would companies bother patented 3BSD if all the "previous designs" had were harrier like STOVL? The patents were in place because there was R&D money coming through the USN pipeline for a different sort of STOVL capability. Multiple companies filled multiple patents in the 1960's and early 1970s, designs were submitted and testing work done. Its just that these designs were not operationalized. R&D without operationalizing happens all the time within the US DOD Industrial base and pretty much any MIC where money is spent to develop capability. Boeing revealed prototypes of RCS reducing airframes and newer materials. Lockheed has revealed the MUTT that is meant to develop a better understanding of flutter and develop a better flutter suppression system. The MUTT will never be operationalized but the systems developed and the patents obtained from its development will be in the possession of the designers to be used on future systems (Next generation bomber most likely). A week or so ago the boss of lockeed's Skunk works devision claimed that 80% of what they work on is classified and for technology development and not operational hardware. Testing, research, development and design refinement has immense value even if these things don't directly find their way into a production ready aircraft. Patents for a 3BSN were developed for the Convair 200 much before any of the Russian STOVL aircraft were revealed to the western world. Pratt owned these patents and therefore did not need to license anything from any russian company. With the need they did not need to go over the YAK and BUY ANTHING, no patent of Yak or any other Russian OEM was ever licensed, in fact the propulsion architecture developed by lockheed through working with their partners was unchanged after YAK's involvement ended. The patents filed and designs submitted during the fly off stage of the program (design submissions) were also unchanged in the final F-35B that flew years later. The X-35B and F-35B had the same propulsion architecture based on the work done over a period that extended through the 90's and incorporated in the patent filled by lockheed before the SDD phase began.
The LiftFan approach was presented by Lockheed in its SSF submissions years before they began working with the Yak designers on the JAST/JSF which was also post the ASTOVL program where lockheed got significant money to develop the architecture that they eventually patented. The maturity of the Liftfan design concept was left to Allison which later got spun off by General Motors to Rolls Royce most likely because rolls royce had such experience as well and they wanted to remain integral player in the US-UK STOVL development efforts. When the design was approved as " Solid" and sound enough to further pursue further funding was made to demonstrate its capability.
At the same time Lockheed was working with YAK full system demonstrations were being planned and executed for the lift fan architecture which lockheed had come up on its own.
Remember this?
The design pictured above was not born out of a few
back of the envelope calculations but years of hard testing, data calculations, product development, going over patents filled decades earlier and working on bringing those thoughts and concepts to modern standards. If one neglects the patents of the 60's and 70's for a moment (which were the basis of the Pratt 3BSN and the Allison Lift fan development) the programs that directly lead to the current architecture/configuration were the SSF, CALF and most importantly the ASTOVL. All these programs pre-date the JAST/JSF program and happened years before lockheed used Yak's consultancy. The STOVL - TEAM that lockheed had gathered included so much volume of test data that it overwhelmed both boeing and General electric. GE rushed in the late 90's to bring its own nozzle designs into the JSF program based obviously on their own research conducted for the AVS programs in the 60's and 70's. From the top of my head i can recall them filing a few patents just before the first prototypes headed for assembly but the Joint strike program had decided by then that if the X-35 and Lockheed's JSF proposal was to win the 3BSN that would be incorporated in the final design would be that designed & produced by Pratt and Whitney irrespective of whether Pratt wins the engine competition. This was the main reason why the extra thrust of GE's engine did not mean much for the competition because the overall thrust increase in the B version of the F-35 was limited not by engine potential but by nozzle performance.
Lockheed pumped in nearly $400 million(in 90s) for three new prototypes and an additional static test aircraft to test improvements in design and avionics
Who contests this? Why would they not spend the money US government provides them to develop their plans into a prototype along with other testing in the lab so that these designs could be evaluated against competition in a formal fly-off ? What does this have to do with YAK? The ASTOVL program lead lockheed towards a path of the current architecture, once they finalized this they went to YAK, they came out of those discussions assured that their plans were solid. They didn't need to change anything from the original pre-YAK architecture. 400 million for essentially maintiang a large industrial design team that involved multi-national aerospace experts, designing and building a prototype for 3 different capabilities is nothing in the larger western context.
The DARPA managed ASTOVL program began in 1983 (No lockheed YAK partnership existed back then) and it was through this effort that lockheed narrowed down on a lift fan + 3BSN approach to a future STOVL fighter - an approach which came back from the studies other's (including lockheed through its acquired companies) had also narrowed down in the 1960s during the AVS program where a similar design was narrowed down upon but that required 2 10K lift-fans and a single rear mounted engine with a 3 bearing swivel nozzle.
The AVS propulsion-design-architecture had filled patents that were owned by Pratt and Whitney for the 90 degree nozzle (Lockheed's team member), Allison for the lift engines (Acquire by Rolls Royce - Lockheed's team member) and Convair for the integrated concept (Whose partial design work lockheed acquired through general dynamics, but who's major IP was still owned by Boeing).
people are not ready to believe that US bought technology from RU when its their in public domain)
What technology was BOUGHT?
the turmeric patent was removed.
