Definition
A vertical structural partition inside an aircraft fuselage that divides the interior into separate compartments and carries loads across the airframe. Bulkheads provide shape and rigidity to the fuselage, transfer concentrated loads (such as those from the wings, landing gear, or engine mounts) into the surrounding structure, and in pressurized aircraft seal off pressurized sections from unpressurized ones.
Plain English
A strong wall inside the aircraft that separates one section from another and helps hold the structure together.
Context Anchor
Seen in aircraft maintenance manuals, inspection reports, and airframe repair discussions.
Derivation
From the old nautical terms 'bulk' (cargo) and 'head' (a wall or barrier). Originally a wall in a ship that separated cargo holds. Aviation borrowed the term because aircraft fuselages, like ship hulls, need internal walls to divide space and carry structural loads.
Why Pilots Care
Bulkheads keep the airframe rigid, separate crew from passengers or cargo, and help contain damage or pressure changes.
Intuition Check
Do not think of a bulkhead as only a simple wall. In an aircraft, a bulkhead is also part of the structure that helps carry and support loads.
Example Sentence 1
The technician inspected the forward bulkhead for cracks before signing off the annual inspection.
Example Sentence 2
Pressurization loads are carried partly by the aft pressure bulkhead.