Definition
A backup display configuration on a glass cockpit (electronic flight display) system that automatically activates when one of the primary display units fails. The remaining functioning display consolidates the most critical flight and engine information onto a single screen so the pilot can continue flying safely.
Plain English
If one of the cockpit screens fails, the other screen automatically rearranges itself to show the most important flight information all in one place, so the pilot still has what they need to fly the airplane.
Context Anchor
Seen in glass-cockpit airplanes during display checks, abnormal procedures, and training for a failed or blank cockpit screen.
Derivation
From 'reversion,' meaning a return to a previous or backup state. The system reverts from its normal split-display setup to a single combined display when needed.
Why Pilots Care
Recognizing reversionary mode prevents loss of situational awareness and allows continued instrument flight with reduced but usable information.
Analogy
Like a car’s digital dashboard dimming and switching to basic gauges when the fancy display fails.
Intuition Check
Reversionary mode does not mean the airplane is flying itself or that the problem is fixed. It means the screen layout has changed so essential information is still available.
Example Sentence 1
When the multifunction display went blank, the system automatically switched to reversionary mode and flight, navigation, and engine data appeared together on the primary flight display.
Example Sentence 2
During the preflight briefing the instructor pointed out the reversionary mode symbology so the student would recognize it in flight.