Definition
Unintended departures from an assigned or target altitude during flight, typically measured in feet above or below the intended altitude. In maneuvers such as steep turns, an altitude deviation is the gain or loss of altitude beyond the tolerance set by the practical test standards or training objective.
Plain English
When the airplane drifts above or below the altitude you were supposed to hold. The bigger the drift, the bigger the deviation.
Context Anchor
Seen during maneuver practice, especially steep turns, when the pilot must keep the airplane at the same altitude while turning.
Derivation
From Latin 'deviare,' meaning 'to turn off the road.' A deviation is a wandering away from the intended path — in this case, the intended altitude.
Why Pilots Care
Uncorrected altitude deviations during steep turns can lead to loss of altitude awareness, airspace conflicts, or disorientation.
Grounding Statement
If the altimeter moves away from the altitude you meant to hold, you are seeing an altitude deviation.
Intuition Check
Do not read “deviation” as any altitude change. In this context, an altitude deviation is an unwanted or unplanned change away from the altitude being held.
Example Sentence 1
During the steep turn, the pilot kept altitude deviations within 50 feet of the entry altitude.
Example Sentence 2
During the 45-degree bank steep turn, the instructor pointed out repeated altitude deviations caused by excessive forward pressure.