In 1932, the Imperial Japanese Navy issued a specification for a long-range floatplane reconnaissance aircraft to replace the Yokosuka E1Y and E5Y, which operated from seaplane tenders and battleships.
Prototypes were requested from Aichi and Kawanishi. Aichi’s submission, the Aichi AB-6 (E7A), or Aichi Experimental 7-Shi Reconnaissance Seaplane, designed by Tetsuo Miki, was influenced by the Heinkel He 62, an example of which Aichi had imported the previous year for a similar evaluation.
The AB-6 was an all-metal biplane with fabric covering and folding wings for shipboard storage, powered by a Hiro Type 91 W12 engine.
It had an enclosed cockpit for its three-man crew: pilot, observer, and radio operator/gunner.
The prototype was completed in February 1933 and took its first flight from Nagoya harbour.
Despite good handling characteristics, its speed, take-off, and landing performance were unsatisfactory, leading to modifications.
The aircraft received new wings with a different aerofoil section and full-span leading-edge slats.
Initially, the Hamilton Standard two-bladed metal variable-pitch propeller was replaced by a two-bladed wooden propeller, and subsequently, a four-bladed wooden propeller.
Nevertheless, Kawanishi’s competing design proved superior and was selected for production in 1934 as the Navy Type 94 Reconnaissance Seaplane, or Kawanishi E7K.
Specifications
Crew
3
Length
10.44 m (34 ft 3 in)
Wingspan
12.98 m (42 ft 7 in)
Height
4.80 m (15 ft 9 in)
Wing area
40.61 m2 (437.1 sq ft)
Empty weight
1,920 kg (4,233 lb)
Gross weight
3,020 kg (6,658 lb)
Max take-off weight
3,300 kg (7,275 lb)
Powerplant
1 × Hiro Type 91, water-cooled W12 engine,
470 kW (630 hp)
Performance
Maximum speed
230 km/h (140 mph, 120 kn) at sea level
Cruise speed
150 km/h (92 mph, 80 kn) at 1,000 m (3,300 ft)
Stall speed
81 km/h (50 mph, 44 kn)
Endurance
11.9 h
Service ceiling
4,850 m (15,910 ft)
Time to altitude
3,000 m (9,840 ft) in 14 min 54 s
Armament
Guns
1× fixed forward firing 7.7 mm machine gun
&
1 flexibly mounted in rear cockpit
&
1 × under fuselage.
Sources Japanese Aircraft 1910–1941-R C Mikesh & A Shorzoe. The Xplanes of Imperial Japanese Army & Navy 1924-1945-Illustrated Warplane History.
