Refer to figures.
Monocoque construction: In a monocoque structure all the loads are taken by the skin with just light internal frames or formers to give the required shape. Even slight damage to the skin can seriously weaken the structure. Extra strength needs to be built in around holes in the structure for windows, doors or undercarriages as these will weaken the structure. This type of construction is only suitable for smaller aircraft. Also called structural skin. Is a French term for "single shell".

Semi-Monocoque construction: As aircraft became larger and the air loads greater the pure monocoque structure was not strong enough and additional structural members known as stringers (stiffeners) and longerons were added to run lengthwise along the fuselage joining the frames together. The light alloy skin is then attached to the frames and stringers by riveting or adhesive bonding. Stringers stiffen the skin and assist the sheet materials to carry loads along their length. Good examples of longerons are the seat rails of passenger aircraft.

Grid construction: Grid or Truss or Framework type generally used for light, non-pressurized, aircraft. The framework consists of light gauge steel tubes welded together to form a space frame of triangular shape to give the most rigid of geometric forms with each tube carrying a specific load the magnitude of which depends on whether the aircraft is airborne or on the ground. It is a strong, easily constructed and relatively trouble free basic structure. The framework is covered by a lightweight aluminium alloy or fabric skin to give an enclosed, aerodynamically efficient load carrying compartment.

Honeycomb structure or Sandwich construction: This is used extensively on aircraft of all types, typically for flight control surfaces, flooring, fuselage panels, empennage skin and sound proofing for engines. It is a laminar construction that uses a Honeycomb core with skins of composite material or aluminium alloy, and it can be used to provide rigidity and strength. It has a good strength to weight ratio and is particularly strong in the direction of the honeycomb openings. Parts made of a Sandwich material need additional provision to carry concentrated loads.

A Tubular steel construction with a non self-supporting skin is referred to as Grid construction.