Folding wing
Folding wings are design features incorporated into aircraft to reduce the amount of space a plane takes up on a deck or other surface, so that more aircraft can be parked in a given area. They are most frequently found on aircraft intended to operate from aircraft carriers, where stowage space on flight decks and hangar decks is at a premium; however, during World War I, in particular, the feature was also used on very large bomber aircraft operating from land, to allow them to fit into hangars designed for smaller aircraft.