Definition
Aircraft components that have a manufacturer-specified maximum allowable operating life, expressed in flight hours, calendar time, or operating cycles, after which the part must be removed from service and replaced regardless of its apparent condition.
Plain English
Parts that have a fixed expiration measured in hours flown, time on the calendar, or number of times used. When that limit is reached, the part must come off the airplane and be replaced, even if it still looks fine.
Context Anchor
Seen in aircraft maintenance records during a preflight assessment, especially when checking whether required inspections, replacements, and time limits are current.
Derivation
Here, “life” means the service life of a part—the amount of use it is approved to have. “Limited” means that service life has a fixed stopping point, not just a suggested check point.
Why Pilots Care
Replacement at the prescribed limit prevents fatigue failure of critical components that could otherwise lead to in-flight malfunction or loss of control.
Intuition Check
Do not assume life limited parts are only parts that look worn out. The limit is based on approved time or use, and replacement is required even if the part looks normal.
Example Sentence 1
Before the flight, the pilot reviewed the maintenance logs to confirm none of the life limited parts had reached their replacement interval.
Example Sentence 2
After the turbine disk reached its 8,000-cycle life limit it was removed and replaced during the scheduled inspection.