Definition
Close to, but not exactly equal to, a stated value. An approximate figure is near enough to the true value to be useful for the purpose at hand, while acknowledging it is not precise.
Plain English
Near enough, but not exact. The number is close to the real value, not the real value itself.
Context Anchor
Seen in performance estimates, position reports, weather descriptions, fuel planning, and general cockpit discussions where a close value is useful but exact precision is not available.
Derivation
From the Latin 'approximare,' meaning 'to come near to' (ad- 'to' + proximus 'nearest'). The word literally describes something that has been brought close to a value without reaching it exactly.
Why Pilots Care
Pilots routinely work with approximate values during flight planning and in-flight adjustments; understanding the acceptable margin prevents over-reliance on imprecise data while still allowing safe continuation of the flight.
Intuition Check
Approximate does not mean careless or made up. It means close to the true value, with some amount of uncertainty still present.
Example Sentence 1
The pilot's operating handbook gives the approximate fuel burn at cruise, so the pilot adds a reserve when planning the flight.
Example Sentence 2
Cruise fuel flow was listed as approximately 11 gallons per hour on the performance chart.