Definition
An airplane upset is an unintentional flight condition in which the airplane has departed from normal cruising or maneuvering parameters. It is generally defined by any of the following: pitch attitude greater than 25 degrees nose up, pitch attitude greater than 10 degrees nose down, bank angle greater than 45 degrees, or flight within these parameters but at airspeeds inappropriate for the conditions.
Plain English
An upset is when the airplane ends up in an attitude or speed the pilot did not intend, well outside the range of normal flying. The nose is too high, too low, the wings are banked too steeply, or the speed is wrong for what the airplane is doing.
Context Anchor
Seen in upset prevention and recovery training, especially when discussing unusual attitudes, loss of control, and recovery actions.
Derivation
From the Middle English upsetten, meaning to set up or overturn. The modern sense of being knocked out of normal position fits aviation use exactly: the airplane has been tipped out of its expected orientation.
Why Pilots Care
Unrecognized upsets are a leading cause of loss-of-control accidents; prompt recognition and recovery are required to prevent them.
Intuition Check
Upset does not mean the pilot is emotionally upset here. It means the airplane itself is out of its normal controlled flying state.
Example Sentence 1
After encountering severe wake turbulence, the airplane rolled past 60 degrees of bank and entered an upset that required immediate recovery action.
Example Sentence 2
Chapter 5 of the handbook explains how to prevent and recover from an upset during high-altitude operations.