Definition
A descent flown on instruments after one or more primary flight instruments have failed, requiring the pilot to maintain a controlled rate of descent using only the remaining serviceable instruments. Most commonly, it refers to descending without the attitude indicator and heading indicator, relying instead on the airspeed indicator, altimeter, vertical speed indicator, turn coordinator, and magnetic compass.
Plain English
Bringing the aircraft down on instruments when some of your main flight instruments have stopped working, using only the ones that are still functioning.
Context Anchor
Used in instrument training and real instrument flying when practicing or handling instrument failures during a descent.
Derivation
"Partial" means "only some," and "panel" refers to the instrument panel in front of the pilot. So a partial panel is a panel where only some of the instruments are available — the rest have failed or been simulated as failed.
Why Pilots Care
Allows continued safe descent and aircraft control when critical instruments are lost, preventing spatial disorientation and loss of control.
Intuition Check
Partial panel does not mean the airplane has a smaller physical panel. It means only part of the normal instrument information is available or usable.
Example Sentence 1
During the checkride, the examiner covered the attitude indicator and asked for a partial panel descent to 3,000 feet.
Example Sentence 2
During the checkride the examiner failed the heading indicator, requiring a partial panel descent while maintaining heading with the turn coordinator.