Definition
A device installed in an aircraft that records the cumulative time a particular system or the engine has been running. In the context of a combustion heater, the hour meter logs total operating hours so that required inspections and maintenance can be performed at the correct intervals.
Plain English
A small counter that keeps track of how many hours something has been used, so you know when it is due for servicing.
Context Anchor
Seen when discussing combustion heater operation, heater inspections, and aircraft maintenance records.
Derivation
Hour comes from an old word for a measured part of the day. Meter comes from a word meaning “measure.” Together, hour meter means a device that measures time in hours, which fits its aviation use as a running-time counter.
Why Pilots Care
Accurate hour readings ensure the heater receives required inspections and overhauls before wear leads to in-flight failure or carbon-monoxide risk.
Analogy
It is like an odometer for the heater. A car odometer counts miles driven; an hour meter counts hours the heater has run.
Intuition Check
Do not read hour meter as a clock. It does not tell the current time of day; it counts accumulated operating time for a system.
Example Sentence 1
Before the flight, the pilot checked the combustion heater's hour meter to confirm it was not due for its scheduled inspection.
Example Sentence 2
Before approving the aircraft for the next trip, the mechanic verified that the combustion heater hour meter had not yet reached its 500-hour inspection interval.