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 Antonov An-225 Mriya is a heavy-lift transport. It was designed to carry piggy-back loads which are too big to fit into its fuselage. For example, the Buran Space Shuttle. Mriya means dream. It is the world's largest aircraft in the world. It was derived from the An-124. The An-225 uses 6 engines, whereas, the An-124 has 4 engines. The An-225 first flew on 21 December, 1988. Only one An-225 was built, however, a second plane may be built.