Soviet / Russian Yakovlev Yak-141 Short Vertical Take-Off and Landing (SVTOL) naval jet

As the F-35 stealth fighters may eventually take on Russian fighters in Europe, the aircraft and its design were a direct spin-off of an old Soviet Union project that failed to materialize when the communist superpower collapsed

The F-35B Short Vertical Take-Off and Landing (SVTOL) naval variant can be considered a direct derivative of the Yak-141.

The Russian company turned to Lockheed Martin in 1991 after the dissolution of the Soviet Union, for some $350 million in funding, as a weakened Russia sought to normalize relations with Washington.

This is reflected in a single vectoring nozzle located behind the centre of gravity and dedicated thrust nozzles located vertically just behind the Yak-141 engine that the F-35B shares.

Design began in 1975 after the Soviet Navy contracted Yakovlev to develop VTOL aircraft capable of defending the air fleet. Under the leadership of renowned aeronautical designer Alexander Yakovlev and his influential Yak 141, they almost made it. The extraordinary machine had four prototypes and broke several world records.

In the midst of the Cold War, in the 1960s, the British Hawker Siddeley Harrier, in both its land and naval versions, was a well-known fighter.

The Soviets first built the Yakovlev Yak-36 ‘Freehand’ with four prototypes. The Yak-38 ‘Forger’ eventually entered production and served the Soviet Navy with over 200 examples.

However, the model was limited in its payload capacity and overall performance. This was partly because Yakovlev aircraft designers and manufacturers always regarded the Yak-38 as a mere step in the development of an advanced VTOL aircraft.

Design

The Soviet Navy wanted the new VTOL aircraft to make up for the Yak-38’s shortcomings: sustained supersonic speed, manoeuvrability, agility, radar and weapons loads.

With unprecedented technical challenges in the design, more than ten chief engineers were forced to work. The challenge was to provide both supersonic performance and maintain thrust vectoring capability.

Engineers eventually adopted the single-engine configuration, as the loss of one engine during landing would result in an immediate roll-over in twin-engine designs. So the designers eventually settled on a nozzle vector behind the centre of gravity.

Dedicated vertical thrust jets were also placed behind the cockpit. Instead, forward thrust and lift were a jet tube at the rear that rotated 90 degrees up and down for VTOL manoeuvres, an arrangement later seen on the F-35B.

The fuselage was designed around an engine concept with a circular nozzle between the twin arms, supporting the distinctive twin-wing tail on either side of the engine mount.

The rest of the Yak-4 shared characteristics with other well-known Soviet aircraft such as the Mikoyan Gurevich MiG-25 and MiG-31. It had a forward fuselage with rectangular air intakes, and its short-area wings were trimmed with a sharp sweep along their leading edges.

The wings can also be folded for easy storage on the carrier. In addition, the required parts were made of titanium, as excessive heat from the engine during landing was expected to damage the fuselage. The non-critical ones were completed with composite materials or graphite.

The flight time was also limited to two and a half minutes to prevent overheating. The engines located behind the cockpit, which were intended for VTOL operations, were covered by dorsal flaps. These provided air to the engines, while exhaust gases flowed into the abdomen and through an opening covered by two abdominal doors.

The main power plant was the Soyuz R-79V-300 turbofan engine, capable of providing 1,088 kg of dry thrust and 15,500 kg of afterburning force. Lift engines behind the cockpit were RD-41 turbojets, each producing 9,000 pounds of thrust.

Performance

The first flight took place on March 9, 1987, and the first successful hover attempt was made two years later on December 29, 1989.

On 13 June 1990, the final prototype achieved the first full transition from high-speed vertical flight to vertical landing. Finally, on September 26, 1991, the first vertical landing on the aircraft carrier was made on the aircraft carrier Admiral Gorshkov.

The aircraft displayed excellent manoeuvrability, great response and kinetic performance for a fighter of its time. It could reach a maximum speed of Mach 1.4 (1,120 mph), a transport range of 1,865 miles, and had a service range of 1,300 miles.

Its service ceiling was over 50,000 thousand feet, while its rate of climb was 48,215 feet per minute.

Lockheed Joins Martin-Yakovlev Design Office

An accident on 5 October 1991 caused substantial damage to one prototype. After a rough landing, the aircraft broke a fuel tank and engulfed in flames when the pilot ejected after 30 seconds and was rescued safely from the sea.

And a few months before the collapse of the USSR, the Soviet Navy announced that there was no more funding to continue the program. The final series production variants with advanced avionics and Leading Edge Route Extension (LERX) were never realized.

The Yakovlev Design Bureau, which was in serious financial trouble, was now looking for cash. And this is where the US defence giant Lockheed Martin invested billions of dollars in the program.

An agreement was signed between the two in 1991, which was not made public until 1995. The fact that the Yak-141 never made it into series production, despite Lockheed’s input, meant that his interest was entirely in the Yak-141’s vital data. Development tests and flights to understand the “learn why” of the technology.

This 1993 document from the National Aeronautics and Space Administration (NASA) acknowledges how important access to Soviet VTOL technology was to the United States: “Based on previously highly classified military hardware and our defence plan, it is now being used at Air Shows around the world. traded openly. … This environment enabled a visit to the Yakovlev Design Bureau (YAK) for an evaluation of vertical/short take-off and landing (VSTOL) technology. Yakovlev is the only FSU design bureau to have experience with VSTOL aircraft and has developed two examples of flight, the Yak-38 ‘Forger’ and the Yak-141′ Freestyle.

The F-35, derived from the Yak-141, will probably be the leader in any combat mission against Russia or China. History repeated itself 20 years later, when it was revealed that China’s J-20 had borrowed heavily from the F-35 through cyber espionage and hacking.