Tubing, Mitsubishi Ha 42 Model 41 Ru (Ha 214 Ru), Radial 18 Engine


Display Status:

This object is not on display at the National Air and Space Museum. It is either on loan or in storage.

Collection Item Summary:

Mitsubishi was the first and largest series producer of Japanese engines during World War II, with a 1937 Pratt & Whitney arrangement possibly contributing to this success. This 18-cylinder, two-row, air cooled aircraft engine incorporated two-speed reduction gearing, a cooling fan, and twin transverse superchargers to achieve two stage supercharging.

Four of these engines were to power the Kawasaki Ki-91 Army Experimental Long-range Bomber, which was to be larger than the Boeing B-29 and have a 4,474 km (2,796 miles) radius of action. The design of this bomber began in May 1943, and a prototype was under construction at the end of 1944, but planned production was suspended in February 1945 when tooling was destroyed during a B-29 raid before the prototype was completed. Between 1940 and 1945, a total of 2,813 Mitsubishi Ha 42 series (all models) were built.

Collection Item Long Description:

Data Source

National Air and Space Museum

Restrictions & Rights

Do not reproduce without permission from the Smithsonian Institution, National Air and Space Museum

Credit Line

Transferred from the U.S. Navy


3-D (356g): 26.4 × 6 × 3.8cm, 0.4kg (10 3/8 × 2 3/8 × 1 1/2 in., 0.8lb.)


Circa World War II

Physical Description

Tubing found inside engine during conservation work prior to 2017 loan. Flattened in middle. One end fitted with elbow joint, open end is threaded. Part appears to be original to engine, damaged at some point. Replacement part was installed at some time prior to conservation work, presumably this piece was placed inside the engine to store the original part.


PROPULSION-Reciprocating & Rotary

Inventory Number