Definition
A comprehensive maintenance procedure in which a component, accessory, or engine is disassembled, cleaned, inspected, repaired as necessary, reassembled, and tested to specified standards. The work restores the item to a defined serviceable condition using procedures and limits published by the manufacturer or an approved data source.
Plain English
A full take-apart, check, fix, put-back-together, and test of a part or engine so it meets approved condition standards again.
Context Anchor
Seen in aircraft and engine logbooks, maintenance records, component histories, and discussions about required or recommended maintenance intervals.
Derivation
From the nautical phrase 'haul over,' meaning to pull a ship over for inspection and repair of its hull. The sense carried into general use as a thorough going-over of any machinery.
Why Pilots Care
Time since overhaul (and time until the next one) affects airworthiness decisions, resale value, and how much confidence you place in an engine or component. Knowing whether a part has been overhauled, and to what standard, matters when reviewing logbooks before flight or purchase.
Intuition Check
Do not assume overhaul means the item is brand-new afterward. In maintenance use, it means the item has been thoroughly inspected, repaired as needed, reassembled, and tested to the required standard.
Example Sentence 1
The engine was sent out for overhaul after reaching the manufacturer's recommended hours.
Example Sentence 2
Following the overhaul, the engine was run on a test stand to verify oil pressure, temperatures, and power output before reinstallation.