Tag Archives: Convair XB-36H Nuclear Test Aircraft

20 July 1955

Convair NB-36 Nuclear Test Aircraft
Convair NB-36H Nuclear Test Aircraft. (U.S. Air Force)

20 July 1955: At Carswell Air Force Base, Fort Worth, Texas, the Convair NB-36H Nuclear Test Aircraft, serial number 51-5712, made its first flight.

In the late 1940s engineers began working on an aircraft that could be powered by a nuclear reactor. The reactor would heat air to provide jet thrust, rather than burning fuel and air to do so. A 60 megawatt reactor was envisioned.

The NB-36 was built to test the shielding requirements of an airborne nuclear reactor and to determine the effects of radiation on aircraft systems.

Convair NB-36H 51-5712. (U.S. Air Force 230502-F-ZS999-1002)

The Nuclear Test Aircraft was built from a Convair B-36H-20-CF Peacemaker strategic bomber, one of 61 that had been destroyed or damaged by a tornado that struck Carswell AFB in 1952. 51-5712 was so heavily damaged that the airframe was written off, but it was rebuilt with a completely new nose section with a shielded cockpit, and was otherwise very heavily modified by Convair. Originally designated XB-36H-20-CF, this was changed to NB-36H in June 1956.

The shielded cockpit unit of the NB-36H (U.S. Air Force)
The shielded cockpit unit of the NB-36H. This assembly weighed 11 tons. (U.S. Air Force)

A one-megawatt Aircraft Shield Test Reactor developed by the Oak Ridge National Laboratory, weighing approximately 35,000 pounds (15,875 kilograms), was installed in the bomber’s aft bomb bay. Though the reactor was fully operational, it did not power the airplane.

As with other B-36s, a combination of six Pratt & Whitney Wasp Major R-4360-53 air-cooled, 28-cylinder radial engines, and four General Electric J47-GE-19 turbojet engines, powered the NB-36.

The Convair NB-36H, 51-5712, with a Boeing B-50 Superfortress. (U.S. Department of Defense DF-SC-83-09332)

The modified bomber could reach a maximum speed of 420 miles per hours at 47,000 feet. It had a maximum gross weight of 357,500 pounds.

During the test program, the NB-36 made 47 flights with a total of 215 hours flight time.

Based on the test results, the entire project was cancelled, and 51-5712 was scrapped at Fort Worth in 1958.

Convair NB-36H Nuclear Test Aircraft 51-5712. (Convair)
Convair NB-36H Nuclear Test Aircraft 51-5712, 6 August 1956. (Convair)

© 2016, Bryan R. Swopes