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:
“We thought it would be worth the while to read the epitaphs where so many were lost at sea; however, as not only their lives, but commonly their bodies also, were lost or not identified, there were fewer epitaphs of this sort than we expected, though there were not a few. Their graveyard is the ocean.”
—Henry David Thoreau (1817–1862)
“The spiral is a spiritualized circle. In the spiral form, the circle, uncoiled, unwound, has ceased to be vicious; it has been set free.”
—Vladimir Nabokov (1899–1977)