Every pilot will lose all sense of direction, height and speed while flying at some point, and some will even feel as though they are sitting on the wing watching themselves in the cockpit, according to a report from the Australian Transport Safety Bureau (ATSB).

The report said between 90 to 100 percent of aircraft pilots experienced “spatial disorientation” (SD) — one of the most common factors in plane crashes.

Aviation medicine specialist Dr. David Newman said pilots were commonly the victims of strange illusions that could be dangerous, and have been linked to between 15 and 26 percent of fatal crashes worldwide.

Some of the most common illusions experienced by pilots included feeling as though the plane was falling when it was slowing down, a false sensation of the aircraft “rolling” and a sense that the plane was not turning when it actually was.

Newman said that there were much stranger illusions experienced by pilots.

“In some cases, pilots may feel that they are sitting out on the wing of their aircraft, watching themselves flying the aircraft,” Newman said in the report.

“The knife edge illusion gives the pilot a sensation that the aircraft is precariously positioned in space, and extremely sensitive to control inputs. By contrast, the giant hand illusion gives the pilot the opposite sensation, that the aircraft is intolerable of control inputs and seemingly immovable in the air, as if held aloft by a giant hand.”

Newman said the illusions often occurred when pilots were not busy flying the plane.

“While seemingly bizarre, these illusions are generally associated with high altitude flight where the pilot has a relatively low level workload. Under such ‘fish-bowl’ conditions, the brain can wander and generate these strange illusions.”

The report said that pilots should be aware that they would experience SD sooner or later.

“If a pilot flies long enough as a career or even a hobby there is almost no chance that he or she will escape experiencing at least one episode of SD,” the report said.

The ATSB report said that pilots should take measures to reduce the impact of SD by flying when fit, not flying under the influence of alcohol or medication, increasing awareness of spatial disorientation illusions and planning for their possible appearance.