Definition
An annunciation or flag indicating that the attitude reference system on a primary flight display (PFD) or attitude indicator has failed and is no longer providing reliable pitch and bank information to the pilot.
Plain English
A warning that tells the pilot the instrument showing the airplane's nose-up/nose-down and wing-tilt position has stopped working correctly and cannot be trusted.
Context Anchor
Seen on electronic flight displays during instrument flying, especially when discussing unusual-attitude recovery and display failures.
Derivation
Attitude comes from a word meaning posture or position. In aviation, it means the airplane’s position in space, not a person’s mood. Fail means the system has stopped providing usable information.
Why Pilots Care
A pilot must immediately transition to partial-panel instruments such as the turn coordinator, altimeter, and vertical speed indicator to maintain aircraft control.
Grounding Statement
When ATTITUDE FAIL appears, treat that attitude display as unusable until a reliable source is available again.
Intuition Check
Do not read attitude as emotional state here; it means the airplane’s pitch and bank. Do not read fail as the whole aircraft failing; it means the attitude information on that display has failed or cannot be trusted.
Example Sentence 1
When ATTITUDE FAIL appeared on the PFD in cloud, the pilot transitioned to the standby attitude indicator and continued the flight on partial panel.
Example Sentence 2
During training the instructor induced an ATTITUDE FAIL to practice recovery using backup instruments only.