Spatial disorientation (SD) is an ever-present risk to aviation but there are many steps that can be taken to minimise the risk of disorientation occurring or leading to an accident, according to a report commissioned by the Australian Transport Safety Bureau (ATSB).
SD, whereby the pilot is unable to correctly interpret aircraft attitude, altitude or airspeed in relation to the Earth, occurs because aviation takes place in a three-dimensional complex environment and the limitations of the normal human orientation systems are exposed in this environment.
It is one of the most common factors contributing to aviation accidents and incidents, according to the report by Dr David Newman, consultant in aviation medicine at Flight Medicine Systems.
SD is estimated to account for 6-32% of major accidents and 15-26% of fatal accidents, although the true prevalence is underestimated. The chance of a pilot experiencing SD during his career is in the order of 90-100%, says the report.
There are three basic types of SD - unrecognised where the pilot is unaware there is a problem recognised where the pilot is aware there is a problem and incapacitating where the pilot is unable to recover from the situation.
The chances of SD occurring in flight can be reduced by a series of preventative measures relating to health and fitness, planning and preparation, and training and education, says the report.
These include flying when fit and well and not under the influence of alcohol or medication being aware of the potential for SD a pilot familiarising himself with the characteristics of the destination runway considering rescheduling a flight if it involves night visual flight rules operations and not attempting to fly into instrument meteorological conditions under visual flight rules.
Pilots should also undertake regular instrument flight exposures as "the ability to properly use flight instruments may make the difference between survival and not", says the report.
There are measures a pilot can take in-flight if a SD event occurs, it adds, including handing over to a second pilot if available, getting out of weather or clouds as soon as possible, requesting help from air traffic control and believing the instruments.
Source: FlightGlobal.com
