longeron
/ˈlɑndʒərɑn/
noun
- A main structural beam or spar that runs lengthwise along the fuselage of an aircraft or the hull of a ship, providing strength and support.
- The wooden longeron in the vintage biplane had to be replaced with a metal one.
- The airplane's longeron was damaged during the hard landing.
- Engineers inspected each longeron for cracks before the flight.