Boeing XB-39 Superfortress
| XB-39 Superfortress | |
|---|---|
| Boeing XB-39 serial number: 41-36954 | |
| General information | |
| Type | Heavy bomber | 
| Manufacturer | Boeing | 
| Primary user | United States Army Air Forces | 
| Number built | 1 | 
| History | |
| Manufactured | 1944 | 
| First flight | 9 December 1944 | 
| Developed from | Boeing B-29 Superfortress | 
The Boeing XB-39 Superfortress was a United States prototype bomber aircraft, a single example of the B-29 Superfortress converted to fly with alternative powerplants. It was intended to demonstrate that the B-29 could still be put into service even if the first choice of engine, the air-cooled Wright R-3350 radial engine, ran into development or production difficulties.