Semi-monocoque

Semi-monocoque is the most popular type of structure used in aircraft nowadays, composed of a long tube shape with a large number of longitudinal reinforcements (stringers) and circumferential reinforcements (frames) which carry all stresses .

The semi-monocoque construction provided higher strength with less weight, the aerodynamic shape required less horsepower to pull (improving gas mileage) and it provided smoother towing.

Incredibly strong, and capable of supporting the weight of several people, the cardboard laminates operate as semi-monocoques with an intermediary plywood armature.