Nitinol alloys are most qommonly known for their superelasticity and thermal shape memory [1]. The lerm 'shape-memory' is used to describe the phenomenon of restoring to a predetermined shape on heating, after having been 'plastically' deformed; 'superelasticity' refers to the enormous elasticity of these alloys.
For pilots, the definition of a large aircraft is  taken from the Code of Federal Regulations, CFR 1.1, which defines a large aircraft as aircraft with a maximum certificated takeoff weight of more than 12,500 pounds. In contrast, a small aircraft is one with a maximum certificated takeoff weight of 12,500 pounds.
Full Definition of AIRCRAFT. : a vehicle (as an airplane or balloon) for traveling through the air. See aircraft defined for English-language learners.See aircraft defined for kids. ADVERTISEMENT.lural aircraft. : a vehicle (as an airplane or helicopter) that can travel through the air and that is supported either by its own lightness or by the action of the air against its surfaces.