Aichi AB-4

1st Flight 1932

Military Users- Imperial Japanese Navy.

The Aichi AB-4 was a Japanese flying boat of the 1930s.

Aichi AB-4

A single engine biplane, the AB-4 was intended to carry out night reconnaissance for the Imperial Japanese Navy.

Six were built and accepted into service as the Experimental 6-Shi Night Reconnaissance Flying boat, three of which were converted to civil transports.

Aichi AB-4

In 1931, the Imperial Japanese Navy instructed the Aichi Tokei Denki Seizo KK, who had been involved in aircraft manufacture, particularly for the Navy, since 1920, to design a small catapult launched night reconnaissance aircraft, intended to observe nocturnal shipping movements, spot naval gunfire during night engagements and to direct friendly submarines.

The resulting design, designated AB-4 by Aichi was a single-engine pusher biplane flying boat of all-metal construction.

Aichi AB-4

Its single-bay wings folded backwards for storage aboard ship, while its crew of 3 were housed in open cockpits.

It was powered by a single Gasuden Urakaze water-cooled six-cylinder inline engine driving a two blade propeller.

The first prototype flew in May 1932, and while handling was generally good, it had poor control during take-off and landing, and a poor view for the pilot.

Despite this, a further five prototypes were ordered for evaluation.

Aichi AB-4


Crew: 3

Length: 9.75 m (32 ft 0 in)

Wingspan: 13.5 m (44 ft 3 in)

AB-4 transport: 14 m (46 ft)

Height: 3.94 m (12 ft 11 in)

AB-4 transport: 3.9 m (13 ft)

Wing area: 47.1 m2 (507 sq ft)

AB-4 transport: 46.02 m2 (495 sq ft)

Empty weight: 1,610 kg (3,549 lb)

AB-4 transport: 1,740 kg (3,836 lb)

Gross weight: 2,350 kg (5,181 lb)

AB-4 transport: 2,550 kg (5,622 lb)

Max takeoff weight: 2,600 kg (5,732 lb) when catapult-launched

Power plant: 1 × Gasuden Urakaze 6-cylinder water-cooled inverted in-line piston engine 224–246 kW (300–330 hp)

Propellers: 2-bladed wooden fixed-pitch pusher propeller


Maximum speed: 164 km/h (102 mph, 89 kn)

Cruise speed: 113 km/h (70 mph, 61 kn)

Stall speed: 84 km/h (52 mph, 45 kn) at 1,000 m (3,281 ft)

Service ceiling: 3,500 m (11,500 ft) (AB-4 transport)

Time to altitude: 2,800 m (9,186 ft) in 60 minutes 50 seconds

AB-4 transport: 2,000 m (6,562 ft) in 23 minutes 20 seconds

Wing loading: 50 kg/m2 (10 lb/sq ft)

AB-4 transport: 49.2 kg/m2 (10 lb/sq ft)

Power/mass: 0.095 kW/kg (0.058 hp/lb)

AB-4 transport: 0.1027 kW/kg (0.0625 hp/lb)


Guns: 1× 7.7 mm (0.303 in) machine gun on a flexible mount in the bow cockpit

Bombs: Flares

Aichi AB-4


Japanese Aircraft, 1910-1941-Robert Mikesh & Shorzoe Abe

Japanese Aircraft of the Pacific War- Rene Francillon.

Japanese Imperial Army & Navy Aircraft Color Markings-Koku Fan Illustrated 42.

Japanese Aircraft Equipment 1940-45-Robert C Mikesh.

Japanese military aircraft illustrated.


Share on facebook

Share on facebook