The Yokosuka R2Y Keiun (景雲, cirrus cloud) was a prototype reconnaissance aircraft built in Japan late in World War II.
== Design and development == Commissioned for the Imperial Japanese Navy, after the R1Y design was cancelled due to its disappointing performance estimates, the R2Y used coupled engines driving a single propeller and also featured a tricycle undercarriage. Completed in April 1945, the prototype made a short flight on 8 May but was destroyed in a US air raid only a few days later, thus ending development. A proposal was also made to develop the R2Y into a turbojet-powered light bomber by replacing its piston engines with two Mitsubishi Ne-330s. Designated the R2Y2 Keiun Kai, it was not constructed before the end of the War.
== Specifications (R2Y1) == Data from Japanese Secret Projects: Experimental Aircraft of the IJA and IJN 1939–1945, Japanese Aircraft of the Pacific WarGeneral characteristics Crew: 2 pilot and radio operator Length: 13.04 m (42 ft 9 in) Wingspan: 13.99 m (45 ft 11 in) Height: 4.23 m (13 ft 11 in) Wing area: 33.99 m2 (365.9 sq ft) Empty weight: 6,015 kg (13,261 lb) Gross weight: 8,100 kg (17,857 lb) Max takeoff weight: 9,400 kg (20,723 lb) Fuel capacity: 1,555 L (411 US gal; 342 imp gal) Powerplant: 1 × Aichi Ha-70 (unified) 24-cylinder liquid-cooled coupled V-12 piston engines, 2,500 kW (3,400 hp) for take-off 2,312 kW (3,100 hp) at 3,000 m (9,800 ft) Propellers: 6-bladed constant-speed metal propeller Performance
Maximum speed: 718.5 km/h (446.5 mph, 388.0 kn) at 10,000 m (33,000 ft) Cruise speed: 463 km/h (288 mph, 250 kn) at 4,000 m (13,000 ft) Landing speed: 166 km/h (103 mph; 90 kn) Range: 3,139 km (1,950 mi, 1,695 nmi) Ferry range: 3,611 km (2,244 mi, 1,950 nmi) Service ceiling: 11,700 m (38,400 ft) Time to altitude: 10,000 m (33,000 ft) in 21 minutes Wing loading: 238.26 kg/m2 (48.80 lb/sq ft) Power/mass: 0.316 kW/kg (0.192 hp/lb)
See also
Aircraft of comparable role, configuration, and era
Heinkel He 119 (tandem-engine with single propeller) Kawasaki Ki-64 (tandem-engine with single propeller) Messerschmitt Me 509 Tupolev Tu-91
Related lists
List of aircraft of World War II
References
=== Bibliography === Francillon, René J. (1979). Japanese Aircraft of the Pacific War (2nd ed.). London: Putnam & Company. ISBN 0-370-30251-6. Millot, Bernard (November 1975). "Le Yokosuka R2Y". Le Fana de l'Aviation (in French) (75): 11–14. ISSN 0757-4169.