Yakovlev Yak-5

The Yakovlev Yak-5 was an experimental trainer aircraft designed by Yakovlev OKB in the Soviet Union, and first flown in 1944. It was the first Yakovlev aircraft to be fitted with a variable-pitch propeller. It did not enter production.^[1]

Development and design

In 1944, the Yakovlev UT-2 was the standard primary trainer of the [[Soviet Air Forces], but its simplicity caused problems when pilots moved on to more sophisticated aircraft, so the Yakovlev design bureau designed a more sophisticated derivative, the UT-2L, which featured an enclosed tandem cockpit, the addition of flaps and blind flying instruments.^[2][3]

At the same time, Yakovlev designed a single-seat aircraft based on the UT-2L, intended as a fighter-trainer. This aircraft, the Yak-5, was a low-wing monoplane of wooden construction, but unlike the UT-2, had the front cockpit removed and an enclosed sliding canopy placed over the rear cockpit. A retractable tailwheel undercarriage replaced the fixed landing gear of the UT-2. It was powered by a Shvetsov M-11Dfive-cylinder radial producing 115 hp (86 kW), which drove a two-bladed variable pitch propeller. It could be fitted with a single synchronized ShKAS machine gun aimed by a reflector sight, while the aircraft was also fitted with a radio.^[4][5]

Operational history

The prototype Yak-5 first flew on 7 September 1944.^[6] The new fighter-trainer's handling proved popular with its test pilots, and the aircraft successfully passed official evaluation. In the end, neither the UT-2L or the Yak-5 entered production because the Soviet Air Force command believed wooden aircraft were becoming obsolete, which would result in production of the all metal Yakovlev Yak-18 trainer in late 1945.^[6][5] The sole Yak-5 was destroyed when it suffered failure of the wooden wing during a snap roll and crashed.^[6][7]

Specifications (Yak-5)

Data from Yakovlev Aircraft since 1924^[6]

General characteristics

• Crew: two, student and instructor
• Length: 7.30 m (23 ft 11⅜ in)
• Wingspan: 10.50 m (34 ft 5⅛ in)
• Height: ()
• Wing area: 17.0 m² (183 sq ft)
• Empty weight: 770 kg (1,698 lb)
• Max takeoff weight: 940 kg (2,072 lb)
• Powerplant: 1 × Shvetsov M-11D 5-cylinder air-cooled radial engine, 86 kW (115 hp)

Performance

• Maximum speed: 250 km/h (135 knots, 155 mph)
• Range: 450 km (243 nmi,280 mi)

References

• Gordon, Yefim, Dmitry Komissarov and Sergey Komissarov. OKB Yakovlev: A History of the Design Bureau and its Aircraft. Hinkley, UK: Midland Publishing, 2005. ISBN 1 85780 203 9.
• Gunston, Bill. The Osprey Encyclopedia of Russian Aircraft 1875–1995. London: Osprey, 1995. ISBN 1 85532 405 9.
• Gunston, Bill and Yefim Gordon. Yakovlev Aircraft since 1924. London, UK: Putnam Aeronautical Books, 1997. ISBN 1-55750-978-6.