For all the yelling and shouting over the Department of Defense’s much-maligned F-35 Joint Strike Fighter program, there’s an unusual, often overlooked footnote in the trillion-dollar project’s history: its origins as an experimental Soviet fighter that only fell into Lockheed Martin’s lap because a desperate Russian aerospace company needed some cold, hard cash.

Before the F-35, there was the Yak-141 ‘Freestyle’ multi-role vertical take-off and landing (VTOL) fighter born during a tumultuous period in Russian military history. Though the Yak-141’s first flight in 1987 was a revolutionary contribution to the development of VTOL systems, the hovering death bird was largely developed as the Soviet Union came apart at the seams, and the newly-broke Russian military was in no position to continue development of the new aircraft after the Berlin Wall.

The Yak-141 manufacturer, Yakovlev, suddenly was faced with the reality of capitalism: Namely, you need money to do cool things. And nearly 30 years after the first flight of the Yak-141, the U.S. Marine Corps is taking off vertically from carriers with it’s F-35Bs. Here’s how the experimental Soviet fighter gave birth to the most controversial aircraft of the modern era.

A Yak-141 performs a barrel roll.

The Soviets get vertical

The Yak-141 was the supposed to be a major technological leap in Soviet Union’s VTOL program, which kicked into high gear in the 1970s after the Soviet Union took note of the iconic Harrier’s development in the UK But the program initially had trouble getting off the ground due to the dismal performance of the Yak-141’s predecessor the Yak-38 ‘Forger,” which Soviet military officials deemed, well, a pile of flying dogshit following its unveiling in 1971.

Despite its functional VTOL system, it lacked the extended combat range of the Harrier as well as reliable radar system and appropriately lethal armament — not to mention the Yak-38’s terrifying automatic ejection seat that both saved lives and surprised the shit out of the pilot when it shot them out of the plane without warning. Although the National Interest argues that the Yak-38 was a concept aircraft that pushed into service to help fill holes in Soviet Naval Aviation and never meant for frontline combat, it was the operational VTOL aircraft in the Soviet arsenal for a decade.

A Yak-38 crashes shortly after take off.

The Yak-141 was specifically designed by Yakovlev to address the shortcomings of the Yak-38, namely speed and range. Two flying prototypes were green-lit and flew in 1987, and the aircraft broke several records that, according to Yakovlev, make it the first aircraft to perform both VTOL flight and supersonic level flight.

But after one of only two prototypes exploded while landing on the aircraft carrier Admiral Groshev in September of 1991, the program was effectively crippled. The Soviet Union was finishing its own economic and political disaster, and the resulting tumult that swept across the Russian military establishment creating a mountain of problems for Yakovlev to overcome if they wanted to see the Yak-141 fly again.

Yak-141 explodes on landing, the pilot ejected and survived.

The Cold War melts

Luckily for Yakovlev, America’s favorite plucky multi-billion dollar defense contractor raced in to save the day. As the Iron Curtain receded across Europe, defense giant Lockheed Martin started to pour money into Yak-141 program in order to glean some sweet, sweet former Soviet engineering secrets. The two companies allegedly signed an agreement in 1991 (but not revealed until 1995) that outlined funding for additional Yak-141 prototypes, including a plan to fly the remaining operational prototype the Farnborough Airshow in September 1992.

While Lockheed most likely had zero intention of helping produce the Yak-141 for export; it would make more sense that the entire contract was a cover for procuring testing data on the Yak-141 program, including most importantly any VTOL data obtained through years of testing and development. And Lockheed wasn’t the only American organization looking to learn from the Soviet-era VTOL program. Consider this document from 1993 that NASA published on the Yak VTOL technology:

Military hardware that had once been highly classified and the basis for our own defense planning was now openly marketed at airshows around the world…This environment permitted a visit to the Yakovlev Design Bureau, (YAK) for a vertical/short takeoff and landing (VSTOL) technology assessment. Yakovlev is the FSU’s sole Design Bureau with experience in VSTOL aircraft and has developed two flying examples, the YAK-38 ‘FORGER’ and YAK-141 ‘FREESTYLE’”

It’s that critical data that likely helped shape the development of the engine systems that are the heart and soul of the modern F-35.

The F-35 Joint Strike Fighter takes off

The X-35 demonstrates STOVL capability.

After the Yakovlev-Lockheed partnership was publically revealed in 1995 and formally ended in 1997, but the Yak-141’s unique designs persisted. When Lockheed entered a VTOL variant of its X-35 demonstrator into the Pentagon’s Joint Strike Fighter (JSF) in 1994, the submitted engine design proposal was radically different from initial proposal developed prior to the Yakovlev deal. Indeed, the VTOL design was changed to ‘ASTOVL Configuration 141’; while it is possible that this name was a coincidence, it’s worth noting for the possible reference to the Yak-141.

It seems likely that the Yak-141 test data was most applied to Lockheed’s VTOL engine design in some way, although the classified nature of the Joint Strike Fighter program makes a clear connection elusive. Air Force Magazine even mentioned the Yak connection in a 1998 feature on Joint Strike Fighter after Lockheed’s F-35 was selected for production.

“The swiveling rear exhaust is a licensed design from the Yakovlev design bureau in Russia, which tried it out on the Yak-141 STOVL fighter. It was all or nothing … If the propulsion concept didn’t work, we obviously weren’t going to be competitive.” Daniels, the Boeing executive, said the lift fan concept was “probably the single most important feature” of the competition.”

To be clear, the F-35’s overall design is not modeled after the Yak-141: The former used a different method for stabilization (see the two jets firing on the front of the plane in the GIF below) and had a different aerodynamic profile. But it’s almost certain that the data gleaned from the old Soviet VTOL project were most likely utilized in the development of the VTOL variant of the F-35 Joint Strike Fighter. And that means the F-35 owes at least part of its existence to a Soviet-era weapons program that never truly took flight.

The Yak-141 Freestyle may not technically count as a predecessor to the F-35, but the JSF does seem to have at least some Russian DNA floating around its engine design — and as the F-35 came to fruition in the United States, the Yak-141 Freestyle died a quiet death in Russia. However, if a resurgent Russian defense industry chooses to move forward with a carrier-based VTOL aircraft, at least one Russian legislator has called for the Yak-141 to be revived, most likely with a stealthier new look for a new Cold War.