3D model
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A procedural model built in Blender from published dimensions, drawings and photographs, painted as Nakajima B6N2 Tenzan (Allied name ‘Jill’) coded ‘コ-B6-11’, a wartime Imperial Japanese Navy aircraft photographed on an airfield in Japan: a three-seat carrier torpedo bomber with a Mitsubishi Kasei 25 fourteen-cylinder radial driving a four-bladed propeller, a long glazed canopy over pilot, navigator and radio operator-gunner, a low folding wing spanning 14.9 m, a fin raked forward to fit carrier lifts and a tailwheel undercarriage, shown tail down on its wheels with a Type 91 torpedo slung offset to starboard: dark green overall, undersides included, a blue-black cowling, light grey main-leg doors and wheel covers, red hinomaru with white surrounds on the fuselage and upper wings and plain red under the wings, the code ‘コ-B6-11’ in white on the fin and rudder, a brown spinner and brown propeller blades with yellow tips (shape from a B6N2 three-view scaled to the published span and length, checked against a second three-view and wartime photographs of this aircraft). Drag to orbit, scroll or pinch to zoom · download .glb (1.1 MB)
Data plate
Specification
- First flight14 March 1941
- Built1,268
- Top speed299 mph
- EngineMitsubishi MK4T Kasei 25 fourteen-cylinder radial, 1,850 hp
- Crew3
- Wingspan14.89 m
- Length10.87 m
- Height3.8 m
- In service1943–1945 (Imperial Japanese Navy)
- RoleCarrier torpedo bomber
- MakerNakajima Hikōki, Japan
- UK collections—
First flight, number built and top speed are for the whole family (B6N2 (Allied name ‘Jill’)); engine, crew and dimensions are for the B6N2 ‘コ-B6-11’ modelled here.
History
The B6N2 ‘Jill’
By 1939 the Imperial Japanese Navy knew that its Nakajima B5N, the torpedo bomber that had led the attack on Pearl Harbor, would soon be outclassed, and it asked Nakajima for a faster successor with a longer range. Nakajima kept the same three-seat layout under a long glazed canopy but gave the new aircraft a far more powerful engine, its own Mamoru radial of about 1,870 hp, and a folding wing. Japanese carrier lifts limited an aircraft to 11 m in length, so the fin was raked forward to keep the tail within it. The first prototype flew in March 1941, and the type was named Tenzan, ‘Heavenly Mountain’.
Testing was slow. The Mamoru vibrated and overheated, and the tail hook and airframe needed strengthening for deck landings, so the B6N1 did not reach front-line units until late in 1943, going into action from Rabaul and in the Solomons. By then the Navy had decided to drop the Mamoru, and the B6N2 was given the proven Mitsubishi Kasei 25 instead, slightly less powerful but far more reliable; it became the main production version. The Allies called the type ‘Jill’.
The Tenzan was fast for a torpedo bomber, but it arrived when the Navy had lost most of its experienced aircrew. At the Battle of the Philippine Sea in June 1944 Tenzans from the carriers were shot down in large numbers by American fighters before they could reach the fleet. For the rest of the war they flew mostly from land bases, making night torpedo attacks with radar-equipped aircraft and, at Okinawa, kamikaze attacks. 1,268 were built in all. The one survivor, a B6N2 taken to the United States after the war, is held in store by the Smithsonian’s National Air and Space Museum.
This airframe
B6N2 Tenzan ‘コ-B6-11’
‘コ-B6-11’ is a B6N2 photographed on an airfield in Japan during the war, in three pictures taken from either side and from the rear quarter, one of them with a torpedo loaded; the unit behind the code is not known. It is modelled because it is the best-photographed single Tenzan: the only surviving example, a B6N2 taken to the United States after the war and displayed outdoors at Naval Air Station Willow Grove, Pennsylvania, until 1981, is kept unrestored and unmarked in store at the Smithsonian’s Paul E. Garber facility in Maryland, and few photographs of it exist. None is in a UK museum. The model shows it standing tail down on its wheels with a Type 91 torpedo slung offset to starboard: dark green overall, a blue-black cowling, light grey main-leg doors and wheel covers, red hinomaru with white surrounds on the fuselage, and ‘コ-B6-11’ in white on the fin and rudder. In the black-and-white photographs the undersides look as dark as the sides, so they are painted green rather than the usual light grey. The upper and lower wing hinomaru and the propeller colours, which the photographs do not show, follow standard practice. Its shape comes from a B6N2 three-view scaled to the type’s span and length, checked against a second three-view and the photographs. The mark is identified as a B6N2 from its Kasei cowling and exhausts, though the code ‘B6-11’ might be read as the B6N1’s Model 11 designation.
Where to see one
Not on charge
The only survivor is held by the Smithsonian’s National Air and Space Museum in the United States.