In aviation, a graveyard spiral is a dangerous spiral dive entered into accidentally by a pilot who is not trained or not proficient in instrument flight when flying in instrument meteorological conditions (IMC).
Graveyard spirals are most common in nighttime or poor weather conditions where no horizon exists to provide visual correction for misleading inner-ear cues. Graveyard spirals are the result of several sensory illusions in aviation which may occur in actual or simulated IMC, when the pilot loses awareness of the aircraft's attitude. In other words, the pilot loses the ability to judge the orientation of his aircraft due to the brain’s misperception of spatial cues.
The graveyard spiral consists of both physiological and physical components. Mechanical failure is often a result but generally not a causal factor, as it is the pilot’s sense of equilibrium which leads to the spiral dive. Flying by “the seat of the pants,” and failing to recognize and/or respond to instrument readings is the most common source of controlled flight into terrain where a plane controlled by a pilot impacts ground.
Read more about Graveyard Spiral: Physics of The Graveyard Spiral, Vestibular Aspects of The Graveyard Spiral
Famous quotes containing the words graveyard and/or spiral:
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—Amanda Theodosia Jones, U.S. beauty contest winner, Miss U.S.A., 1973. As quoted under the pseudonym “Emma Wright” in American Dreams, Prologue, by Studs Terkel (1980)
“Year after year beheld the silent toil
That spread his lustrous coil;
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Stole with soft step its shining archway through,
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—Oliver Wendell Holmes, Sr. (1809–1894)