Definition
A change made to the design, configuration, or components of an aircraft, engine, propeller, or appliance after it has left the factory. In FAA-regulated aviation, modifications must be performed using approved data and documented appropriately, because they alter the certified configuration of the aircraft.
Plain English
A change to an aircraft or one of its parts after it was originally built, done in an approved way and recorded properly.
Context Anchor
Seen in maintenance records, aircraft logbooks, equipment discussions, and paperwork for changes made to an aircraft.
Derivation
From Latin modificatio, meaning 'a setting of bounds' or 'a measured change.' In aviation, it carries that idea of a controlled, bounded change — not just any alteration, but one done within approved limits.
Why Pilots Care
Unapproved modifications can affect safety and airworthiness, potentially grounding the aircraft or creating legal issues.
Intuition Check
Modification does not mean any small adjustment or repair. In aviation, it usually means a change to the aircraft or its equipment that may need proper approval and a maintenance record.
Example Sentence 1
The avionics shop completed the modification to install the new GPS unit and signed off the paperwork before the aircraft returned to service.
Example Sentence 2
All modifications must be inspected and logged before the next annual inspection.