Which Boeing aircraft was nicknamed the Stratocruiser?

The Boeing 377 was nicknamed the Stratocruiser.

The Boeing 377 Stratocruiser was a large piston-powered airliner derived from the C-97 Stratofreighter military transport, which itself was based on the B-29 and B-50 bomber family. Boeing introduced the aircraft after World War II to serve long-distance international routes with greater passenger comfort.

Its distinctive double-lobed fuselage created a spacious main cabin and a lower lounge reached by a spiral staircase. The aircraft also featured pressurization, sleeping berths on some configurations, and a roomy interior for its era. Pan American World Airways inaugurated Stratocruiser service in 1949.

The name is sometimes confused with the Boeing 307 Stratoliner, an earlier pressurized airliner. The 307 was the first commercial airliner with a pressurized cabin, while the 377 was the later, larger Stratocruiser. The 377’s piston engines and high operating costs limited its commercial success once jet airliners arrived.