Graveyard Spiral - Physics of The Graveyard Spiral

Physics of The Graveyard Spiral

The impression given by the senses in that situation would be level flight, with a descent indicated on the altimeter and vertical speed indicator. This usually leads to the pilot "pulling up" or attempting to climb by pulling back on the control yoke. In a banking turn, however, the plane is at an angle and will be describing a large circle in the sky. Pulling back on the control yoke has the effect of tightening that circle and causing the plane to lose altitude at an increasing rate. An increasing component of the lift being generated by the wings is directed sideways by the bank angle. At that point the aircraft is describing a descending circle or spiral. In the ever-tightening, descending spiral the aircraft eventually exits the base of the clouds and/or impacts the ground.

To avoid this situation, a student pilot or a pilot under instruction uses a view limiting device to learn instrument flying proficiency under the supervision of a flight instructor. Instrument-rated pilots also use view-limiting devices supervised by an instructor or a safety pilot to practice instrument flight and maintain instrument flying proficiency.