Definition
A scheduled, comprehensive maintenance procedure in which an aircraft engine is disassembled, inspected, cleaned, repaired, and reassembled to restore it to a serviceable condition that meets specified manufacturer or regulatory limits. An overhaul typically involves replacing worn parts, measuring components against service tolerances, and testing the rebuilt engine before it is returned to service.
Plain English
An engine overhaul is a major service where the engine is taken apart, checked, repaired, and put back together so it works like it should again.
Context Anchor
Seen in aircraft maintenance records, aircraft logbook discussions, pre-purchase inspections, and questions about how many hours an engine has run since major maintenance.
Derivation
Overhaul' comes from the old nautical term meaning to haul rigging over for inspection and repair. The sense carried into mechanical work: pulling something apart thoroughly to check and restore it. That history fits the aviation meaning well — an overhaul is not a quick fix, it's a top-to-bottom restoration.
Why Pilots Care
Ensures engine reliability and airworthiness; required at manufacturer-specified intervals to prevent in-flight failures.
Intuition Check
Do not read overhaul as just “repair.” In aviation, an engine overhaul is a major teardown, inspection, repair as needed, reassembly, test, and record entry.
Example Sentence 1
The Cessna had 1,400 hours since its last engine overhaul, leaving room before the recommended 2,000-hour limit.
Example Sentence 2
Following the engine overhaul, the logbook entry documented all replaced components and the new total time in service.