On 7 July 1962, Georgy Mosolov flew a sleek Soviet delta-winged jet down a measured course twice, once in each direction, and averaged 2,681 kilometres per hour. That made it the fastest aircraft in the world. The paperwork sent to the Fédération Aéronautique Internationale, which certifies world records, named the aircraft the E-166.

There was no such aircraft. The jet Mosolov flew was the first Mikoyan Ye-152 prototype, and "Ye-166" was a designation invented for the record books. Even today, the aircraft wearing that name in Russia's Central Air Force Museum at Monino is not the one that set the records.

An Interceptor That Never Was

The Ye-152 grew out of the Ye-150, a heavy interceptor Mikoyan designed for the Soviet air defence forces. The Ye-150 first flew on 8 July 1960 and in manufacturer tests reached Mach 2.65 at 19,100 metres. From it came two single-engine Ye-152s, each powered by the new Tumansky R-15-300, a big afterburning turbojet of around 100 kilonewtons.

According to the Russian test-pilot archive testpilot.ru, Mosolov took the first prototype, Ye-152-1, into the air on 21 April 1961, and the second, Ye-152-2, followed on 21 September 1961. The aircraft looked like a stretched, heavier MiG-21: a long, slim fuselage, a delta wing and a cone in the nose intake. This Day in Aviation lists a length of 19.66 metres and a take-off weight of about 14,350 kilograms.

The weapon system it was built around, the Uragan-5 guidance system with K-9 missiles, was cancelled in 1962. Combined with the R-15's poor reliability at the time, that ended the Ye-152 as an interceptor programme.

Three Records Under a False Name

Before that happened, the first prototype set three world records, all registered with the FAI as the E-166. In October 1961, Alexander Fedotov flew it at 2,401 kilometres per hour around a 100-kilometre closed course. On 7 July 1962, Mosolov set the absolute world speed record of 2,681 kilometres per hour over a 15-to-25-kilometre straight course, averaging two runs in opposite directions. And on 11 September 1962, Pyotr Ostapenko reached 22,670 metres in sustained horizontal flight.

Mosolov's speed record beat the 2,585 kilometres per hour set by an F4H-1F Phantom II in November 1961, and it stood until 1 May 1965, when a Lockheed YF-12A raised the mark to 3,331.5 kilometres per hour.

Why Invent a Name

The Soviet Union often gave record aircraft misleading designations when filing with the FAI. It kept Western intelligence guessing about what was really flying, and which aircraft were prototypes for which programmes. The "E-166" is one of the best-known examples, and the trick worked: the name still appears in record lists today, with a note that it was really a Ye-152.

The deception has outlived the Cold War in a very physical way. After the programme ended, the second prototype, Ye-152-2, was converted into the Ye-152M with a new nozzle, and later lost its canards. That is the aircraft standing at Monino, painted "E-166" with three red stars for records it never flew. The record breaker itself, Ye-152-1, was also converted, into a test aircraft for another intercept system.

What Came Next

The Ye-152 never entered service, but its engine family did. The Tumansky R-15 went on to power the MiG-25 Foxbat, the Mach 3 interceptor that would become the Soviet Union's most famous speed machine. Mosolov, who had already been named a Hero of the Soviet Union in 1960, set six world speed and altitude records in his career. He died in Moscow in 2018, aged 91.

The Animarchy History video below looks at the Ye-152 and its record-breaking career.

Sources: Wikipedia (Mikoyan-Gurevich Ye-152; List of flight airspeed records); This Day in Aviation; testpilot.ru; Yefim Gordon, Soviet Heavy Interceptors (2004), as cited by Wikipedia