Why did US allow Lockheed to fund Russia's development of the Yak-141 VTOL aircraft after the Soviet collapse? And why was development abandoned?
@gelgoog is mostly correct except for a few details.
First, The Yak 141 predates the fall of the Soviet Union. Its first flight was in 1987. The program was scraped in September 1991 after the Soviet economy gave up the ghost. So it was canceled because at that time the Russian military machine was broke. This was around the same time the Russians were giving naval ships to Pepsi and tanks to South Korea. As Gelgoo explained it was a different era and the U.S. and Russia were much more willing to work together. After the cancellation a year later Yak announced they had a partner.
Second What Lockheed bought wasn’t the design of the Swivel. They bought the test data. But they didn’t use that to design the lift system they used it to check the maths. The lift system for the X35 was designed in
< link to patent which gives a filing date of 1990.
Again Yak announced their partnership in 1992. The design for the X35 lift system had already been completed in 1990.
So where did it come from? deep in Lockheed Martin’s archives they already had their own 3 bearing swivel nozzle.
The Convair corporation had in the 1970s a design for a new fighter to meet a requirement the U.S. Navy was looking at. The Sea Control ship would have been something akin to the modern Queen Elizabeth class carrier. To operate off the deck the navy wanted a super sonic SVTOL fighter. Convair model 200 was their solution.
The 200 as you can see would have been a delta wing conard fighter something more common is European. The jet would have used a set of two vertically mounted Jet engines to provide vertical thrust and a 3 bearing swivel on the main engine.
Prat and Whitney had designed the 3 baring swivel that was to be used for the Convair 200! as far back in the
. <link to the Patent.
The Convair 200 was never built. The SCS was canceled before anything ever came of it.
In the 1980s as programs that would eventually merge into the JSF and the X35 Lockheed eventually Lockheed Martin went over their old projects and set to use the Convair design as a base in combination with a new lift fan design by Rolls Royce.
So where does Yak come in? Well again the Convair 200 never progressed to an actual flying prototype. They had drawings and models a test article or two. Computer generated projections. Then the Cold War ended and Russia had basically built one. The Yak 141 was basically a metric Convair 200. Engineers love hard data. The Russians had it and were going to do nothing with it. So $$$. Yak got some money and LM and the JSF office got a delivery of bathroom reading materials.