Definition
The total elapsed time, measured in hours and minutes, that a flight crew member has been continuously awake prior to or during a flight. It is used as a fatigue indicator in human-factors and crew-rest considerations, since extended time awake degrades alertness, judgment, and reaction time regardless of total flight or duty hours.
Plain English
How long you have been out of bed and awake. The longer you've been up, the more tired you are — and tiredness affects how well you fly.
Context Anchor
Seen in fatigue, rest, and personal fitness-to-fly decisions before or during a flight.
Why Pilots Care
Excessive time awake degrades alertness, decision-making, and reaction speed, raising the risk of errors during takeoff, approach, or other critical phases.
Grounding Statement
If you woke at 0500 and are still preparing to fly at 2100, your time awake is 16 hours, even if only part of that time was spent flying.
Intuition Check
Do not treat time awake as only time spent on duty or in the airplane. It includes the whole stretch since your last real sleep, including commuting, waiting, delays, and preflight preparation.
Example Sentence 1
By the time we reached the destination, my time awake was over 14 hours, and I could feel my concentration slipping on the approach.
Example Sentence 2
Company policy requires a full crew rest period once time awake exceeds the prescribed maximum.