Fuselage construction types
Evolved wood truss, then monocoque, then semimonocoque (current). Composite is newer, emerging (PHAK ch.3).
| Type | What carries the load | Note |
|---|---|---|
| Truss | Welded steel or aluminum tubing: longerons plus welded vertical and horizontal struts; strength from triangular shapes | Square or rectangular shape seen from the end. Main drawback: lack of a streamlined shape |
| Monocoque | Stressed skin carries almost all loads, like an aluminum beverage can | Very strong, but not tolerant of surface deformation: a slightly dented can collapses. May include bulkheads, no stringers |
| Semimonocoque ("partial") | Stressed skin plus a substructure of bulkheads and/or formers and stringers | Substructure takes some bending stress |
| Composite | Fibers (fiberglass, carbon fiber, Kevlar) carry most of the load in a matrix (the "glue" that holds the fibers and gives the part its shape) | Extremely smooth skins, easy complex curved or streamlined shapes |
Trap: skin as only load carrier is monocoque; semimonocoque shares load with bulkheads/formers and stringers.
References
- FAA-H-8083-25 PHAK ch.3 (Types of Aircraft Construction) and glossary