Sukhoi Su-5

The Sukhoi Su-5 or I-107 was a Soviet mixed-power (propeller and motorjet) prototype fighter aircraft built toward the end of World War II.

Development

The appearance of German turbojet-powered Messerschmitt Me 262 near the end of WWII prompted Soviet Union to develop faster fighter aircraft. Since USSR lacked a production-ready turbojet engine, the efforts were directed toward mixed-power aircraft utilizing a conventional piston engine-driven propeller for the majority of propulsion with a small rocket or jet engine for bursts of speed.

The Su-5 (initially I-107) and the conceptually similar Mikoyan-Gurevich I-250 (N) were designed in 1944. The aircraft first flew on 6 April 1945 and underwent limited flight testing. It was subsequently fitted with a laminar flow wing and attained 793 km/h (428 knots, 493 mph) at 4350 m (14,270 ft) with the motorjet functioning. On 15 June 1945, the Klimov VK-107A piston engine was damaged beyond repair in flight. Following acquisition of another VK-107A, flight testing continued until 18 October when the engine reached the end of its service life. No further VK-107As could be procured and the project was canceled.
The Su-5 was a conventional monoplane of all-metal construction. The VDRK (Russian: Воздушно-Реактивный Двигатель Компрессорный) motorjet in the rear of the fuselage was powered by a driveshaft from the VK-107 piston engine and could provide an additional 100 km/h (54 knots, 62 mph) of speed for three minutes.

Specifications (Su-5)

General characteristics

* Crew: 1
* Length: 8.51 m (27 ft 11 in)
* Wingspan: 10.56 m (34 ft 8 in)
* Height: 3.53 m (11 ft 7 in)
* Wing area: 17 m² (183 ft²)
* Empty weight: 2954 kg (6,510 lb)
* Loaded weight: 3804 kg (8,390 lb)
* Powerplant:
o 1× VDRK motorjet, 2.9 kN (660 lbf)
o 1× Klimov VK-107A liquid-cooled V12 engine, 1230 kW (1,650 hp)

Performance

* Maximum speed: 810 km/h (437 knots, 503 mph) projected at 7800 m (25,590 ft)
* Range: 600 km (325 nm, 375 mi)
* Service ceiling 12000 m (39,370 ft)
* Rate of climb: 5.7 min to 5000 m (16,405 ft)

Armament

* 1x 23 mm (0.91 in) Nudelman-Suranov NS-23 cannon
* 2x 12.7 mm (0.50 in) Berezin UB machine guns