The Aichi F1A (designated AB-13 by its designers and manufacturers at Aichi) was a prototype Japanesefloatplane of the 1930s. A single-engined biplane, the F1A was intended as a short-range observation aircraft suitable for operation off the Imperial Japanese navy's warships, but only two were built, the Mitsubishi F1M being selected instead.
Design and development
The F1A was designed by Aichi in response to a 1935 specification, issued to Aichi, Kawanishi and Mitsubishi for a replacement for the Imperial Japanese Navy's Nakajima E8Nfloatplanes, which were used for short-ranged reconnaissance and observation missions from the Navy's warships. Aichi at first considered a low-winged monoplane design, the AM-10, to meet this requirement, but this was rejected in favour of a more conventional biplane design, the AB-13.[1][2]
The AB-13 was a small single-bay biplane of mixed construction. It had wooden stressed-skin wings with plywood skinning that folded to allow easy storage aboard ship, while combat flaps were fitted as the aircraft was required to have sufficient maneuverability for air combat as well as its normal observation missions. The fuselage was of metal construction, with the pilot sitting in an open cockpit, but the observer's position being enclosed. Both float and wheeled undercarriages were designed, with the seaplane having a single main float, while the landplane version had a fixed tailwheel undercarriage. Power was provided by a single Nakajima Hikariradial engine.[3]
Operational history
Two prototypes of the AB-13, designated Experimental 10-Shi[a] Observation Aircraft and with the short system designation F1A were built, the first a floatplane and the second with wheeled undercarriage, both being completed in 1936.[3] Although Mitsubishi's competing F1M1 prototypes had poor stability both on the water and in the air, they had superior performance to Aichi's design. Mitsubishi redesigned its aircraft as the F1M2, eliminating its handling problems,[4] and it was selected for production in 1940.[5]
Maximum speed: 386 km/h (240 mph, 207.8 kn) at 3,000 m (9,840 ft)
Stall speed: 95.4 km/h (59.3 mph, 51.5 kn)
Range: 1,449 km (900 mi, 783 nmi) at 185 km/h (100 knots, 115 mph)
Endurance: 8 hr 30 min
Service ceiling: 9,275 m (30,430 ft)
Time to altitude: 3,000 m (9,840 ft) in 4 min 26 s
Armament
Guns: 2× fixed forward firing 7.7 mm machine guns, 1 machine gun in rear cockpit
References
Footnotes
a In the Japanese Navy designation system, specifications were given a Shi number based on the year of the Emperor's reign it was issued. In this case 10-Shi stood for 1935, the 10th year of the Shōwa era.[6]
Francillon, Ph.D., René J. Japanese Aircraft of the Pacific War. London: Putnam & Company Ltd., 1970. ISBN0-370-00033-1 (2nd edition 1979, ISBN0-370-30251-6).
Mikesh, Robert C. and Shorzoe Abe. Japanese Aircraft, 1910–1941. London: Putnam Aeronautical, 1990. ISBN0-85177-840-2.
1 X as second letter is for experimental aircraft or imported technology demonstrators not intended for service,
2 Hyphenated trailing letter (-J, -K, -L, -N or -S) denotes design modified for secondary role, 3 Possibly incorrect designation, but used in many sources