Definition
Aircraft parts or components that the manufacturer or regulating authority has assigned a maximum allowable service life, expressed in flight hours, calendar time, or operating cycles, after which the item must be removed from service and replaced regardless of its apparent condition.
Plain English
Parts on the aircraft that have a fixed expiration — once they reach a set number of hours, cycles, or calendar time, they must be replaced, even if they still look and work fine.
Context Anchor
Seen in aircraft inspection and maintenance-record discussions, especially when checking whether an aircraft is still safe and legal to fly.
Derivation
‘Life-limited’ literally means the part has a limit on its useful life. The phrase is used because the limit is set in advance by engineering analysis — not by waiting for the part to wear out or fail.
Why Pilots Care
Following these replacement schedules keeps the aircraft airworthy and prevents failures of critical components.
Intuition Check
Do not read life-limited items as simply “parts that might wear out someday.” In aviation, it means parts with a fixed required removal limit that must be tracked.
Example Sentence 1
During the annual inspection, the mechanic flagged a life-limited item on the engine that was approaching its replacement interval.
Example Sentence 2
During the annual inspection the owner confirmed the status of every life-limited item before approving the aircraft for return to service.