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.
The Largest Airplane Ever Built. The Antonov An-225 Mriya is a cargo aircraft that was designed by the Soviet Unionâs Antonov Design Bureau in the 1980s. It is powered by six turbofan engines and is the longest and heaviest airplane ever built, with a maximum takeoff weight of 640 tonnes. It also has the largest wingspan of any aircraft in operational service. Only one An-225 was ever built and the behemoth transporter is still in service today. The first and only An-225 was completed in 1988 after four years of construction. The An-225 first flew on 21 December 1988 with a 74-minute flight from Kiev.