In an aircraft, the mainspar is the structural piece of the airframe that extends across the fuselage and down the wings; it essentially bears the weight of the aircraft in suspending it from the wing structure and keeps the wings correctly aligned. Cutting the mainspar is sometimes done on military aircraft sold as surplus to ensure that they will never again be able to perform at their design loads, and not at all without skilled and expensive repairs.

Log in or register to write something here or to contact authors.