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.
Heavy vs Large vs Small Aircraft. Additionally, the term large with respect to aircraft means one thing to air traffic controllers and another thing to pilots. A heavy aircraft, according to the FAA's Air Traffic Control Policy, Order JO 7110.65V, effective April 3, 2014, is one that is capable of taking off at a weight of 300,000 pounds or more. The key word is capable - an aircraft can operate with less than 300,000 pounds during takeoff and still be classified as heavy under this air traffic control policy. A large aircraft is one with a maximum certified takeoff weight of more than 41,000 pounds and less than 300,000 pounds. A small aircraft is one with a maximum certified takeoff weight of 41,000 pounds.