Definition
A unit of time equal to 60 minutes, used in aviation to express flight time, duty time, fuel endurance, maintenance intervals, and forecast or report validity periods.
Plain English
Hour. A standard 60-minute period of time.
Context Anchor
Seen in FAA abbreviation lists, flight planning notes, aircraft records, and other aviation documents where time is written in a compact form.
Derivation
Hour comes through Old French from Latin hora, meaning a period of time. The abbreviation HR keeps the main consonants of hour so the time unit can be written quickly in charts, notes, and records.
Why Pilots Care
Accurate time tracking in hours is essential for fuel planning, maintenance scheduling, and regulatory compliance.
Intuition Check
Do not read HR here as human resources or heart rate. In this aviation abbreviation list, HR means hour: a 60-minute period of time.
Example Sentence 1
The aircraft has 2.5 HR of fuel remaining at current power settings.
Example Sentence 2
Endurance is listed in HR on the performance chart.