The term semi-monocoque or semimonocoque refers to a stressed shell structure that is similar to a true monocoque, but which derives at least some of its strength from conventional reinforcement.
Semi-monocoque aircraft fuselages differ from true monocoque construction through being reinforced with longitudinal stringers.
[1][2] The Mooney range of four seat aircraft, for instance, use a steel tube truss frame around the passenger compartment with monocoque behind.
[3] The British ARV Super2 light aircraft has a fuselage constructed mainly of aluminium alloy, but with some fibreglass elements.
[4] Peter Williams' 1973 Formula 750 TT-winning John Player Norton racer was an early example of a semi-monocoque motorcycle.