The graveyard spiral is characterized by the pilot mistakenly believing he or she is in wings-level flight when the aircraft is in fact engaged in a banking turn, and notices the altimeter indicating an ongoing drop in altitude. The sensory disorientation of returning from a prolonged banking turn to wings-level flight can cause the pilot to re-enter the banking turn, as in the graveyard spin illusion. While the plane continues in the turn and begins to indicate a loss of altitude, the pilot will try to correct the loss of altitude by "pulling up" on the plane's controls. Attempting to adjust the controls in this way will have the effect of tightening the radius of the turn and eventually quickening the rate of descent until the pilot is visually cued to the nature of the error or contact with the terrain occurs. One of the most famous cases of an aircraft mishap from this form of spatial disorientation was the crash that killed John F. Kennedy Jr. over Martha's Vineyard in 1999.