Convair NB-36H

The Convair NB-36H, Serial 51-5712, was a shield test aircraft used for the X-6 programme.

Description
Sometimes known as the Crusader, the NB-36 was intended to prove the feasibility of carrying a nuclear reactor in flight, towards an eventual goal of a nuclear-powered aircraft with unlimited endurance. The NB-36H was built using components from a B-36H-20-CF damaged at Carswell Air Force Base, also at Forth Worth, by a tornado on 1 September 1952. A new nose compartment, heavily lined with lead and thick yellow tinted glass to protect the crew from radiation was installed. The consequences of an NB-36H crash were so frightening that several support planes, including one filled with a team of paratroopers, followed the aircraft on every flight. Should the NB-36H crash or have to jettison its reactor, they would jump and secure the site and help with clean-up. A hotline to the president's office was set up in case of disaster. It was nearly used on one flight when a smoke marker went off in the reactor compartment.

The five-man crew, which included a pilot, copilot, flight engineer and two nuclear engineers, were located in the forward section of the aircraft, while the atomic reactor was located in the rear section. The crew were so isolated from the engines and the outside world because of the thick shielding that they could barely hear the very noisy engines and likened the experience to flying a submarine.

The engines of a normal B-36 were inspected in flight by the aft crew members. On the NB-36H this was done by a television camera system, as was observation of the reactor itself. The reactor did not power the aircraft or any of its systems. It was only operated when the XB-36 was over a test range in New Mexico.

Known as the Nuclear Test Aircraft (NTA) it redesignated XB-36H, then NB-36H, and was modified to carry a three megawatt, air-cooled nuclear reactor in its bomb bay. The reactor, named the Aircraft Shield Test Reactor (ASTR), was operational but did not power the plane. The NTA completed 47 test flights and 215 hours of flight time (during 89 of which the reactor was operated) between July 1955 and March 1957 over New Mexico and Texas. This was the only known airborne reactor experiment by the USA with an operational nuclear reactor on board.