If the longitudinal members are numerous (usually 50 to 100) and are placed just between two formers/frames, then they are called "stringers". ... Longerons often carry larger loads than stringers and also help to transfer skin loads to internal structure. Longerons nearly always attach to frames or ribs.

What is the function of longerons in fuselage?

Sometimes confused with, and referred to interchangeably as stringers, longerons are spar-like structures that run lengthwise of the airplane's fuselage or span wise of a wing. The purpose they serve is to transfer loads and stresses from the aircraft's skin to the formers.

What is a stringer in aircraft?

Stringer (aircraft), or longeron, a strip of wood or metal to which the skin of an aircraft is fastened.