FAA Aviation Mechanic Airframe (AMA)Airframe StructuresEasy
A technician is examining a fuselage design in which the smooth outer skin alone carries all primary bending, torsional, and shear loads, with no internal longitudinal stiffening members such as stringers or longerons. This type of fuselage structure is best classified as which of the following?
- AMonocoque
- BTruss type
- CGeodesic
- DSemi-monocoque
Show answer & explanationAnswer & explanation
Correct answer: A. Monocoque
A monocoque structure relies entirely on the skin to carry all structural loads, with formers/bulkheads only maintaining shape. Because there are no stringers or longerons reinforcing the skin, this is a pure monocoque design.
Why the other options are wrong
- B. Truss type uses a welded tubing framework, not skin, to carry loads.
- C. Geodesic uses a lattice/basket-weave framework, not a plain skin shell.
- D. Semi-monocoque adds stringers and longerons to share loads with the skin.
Monocoque Structure
A fuselage design in which the outer skin carries all primary stress loads, with internal formers/bulkheads only used to maintain shape.
- Skin alone bears bending, torsion, and shear loads
- No stringers or longerons present
- Heavier skin required than semi-monocoque designs
- Rare in modern aircraft due to weight penalty
Memory trick: Mono = one shell doing all the work.