The Jesus nut or Jesus pin is the master rotor retaining nut that holds the main rotor of the helicopters. It is a fist-sized steel part, which holds the weight of the aircraft by the top of the mast. The term Jesus nut was said to have been established by American soldiers in Vietnam. Jesus nut or pin is a moniker that is widely used in literature.
If the Jesus nut were to fail during flight, the helicopter would disconnect from the rotor, and the only thing for the crew to do would be to "pray to Jesus." The technical term for the Jesus nut is the main rotor retaining nut.
