Definition
A structural member used in a semi-monocoque fuselage to give the aircraft its cross-sectional shape and to support the outer skin. Formers run around the fuselage (perpendicular to the length of the aircraft) and work together with longerons and stringers, which run lengthwise.
Plain English
A curved frame inside the fuselage that holds the shape of the aircraft, like a rib running around the body, with the metal skin attached to it.
Context Anchor
Seen in airframe structure descriptions, maintenance manuals, inspection notes, and repair drawings for fuselage sections.
Derivation
From the verb 'to form.' A former is literally the part that forms the shape — it gives the fuselage its outline.
Why Pilots Care
Formers carry shape and load. Damage to a former is a structural issue, not a cosmetic one, and repairs must follow approved methods to keep the fuselage strong.
Intuition Check
Former does not mean “previous” here. In this context, it means a part that forms or shapes part of the aircraft structure.
Example Sentence 1
The technician inspected each former for cracks before reattaching the fuselage skin.
Example Sentence 2
Formers are attached to the longerons to keep the fuselage round and strong.