Definition
A category of recorded flight time logged against particular components or events of an aircraft's operation rather than total airframe hours. Examples include time in service, time since new, time since overhaul, time since last inspection, and time since installation of a specific component. These figures are tracked separately in the aircraft's maintenance records and are used to determine when inspections, overhauls, or component replacements are due.
Plain English
Different ways of measuring how many hours an aircraft or one of its parts has been used, counted from different starting points. For example, hours since the engine was overhauled, or hours since the last annual inspection.
Context Anchor
Seen in flight planning, position reports, dispatch records, and air traffic control coordination when people need to know when an aircraft will pass, or did pass, a certain point.
Why Pilots Care
Allows accurate estimation of arrival times, fuel consumption, and coordination to maintain safe separation from other traffic.
Grounding Statement
If a route has several named points, this term refers to the clock time connected with the aircraft crossing each one.
Intuition Check
Do not read this as the amount of time an aircraft spends at a point. It means the clock time when the aircraft reaches or passes that point.
Example Sentence 1
Before signing off the aircraft for flight, the mechanic checked the time at specific points for the aircraft to confirm no inspections were overdue.
Example Sentence 2
ATC asked for the time at specific points for the aircraft during the climb to verify routing.