Spatial Disorientation
SPATIAL
DISORIENTATION
The Importance of Awareness in
Aviation
Shanal Perera
HES1915A - Human Performance and Limitations in Aviation
Introduction
One of general aviation 's biggest killers - Spatial Disorientation (SD). It is the inability to correctly interpret aircraft attitude, altitude or airspeed in relation to the Earth or other points of reference. Any condition that does not allow the pilot to maintain natural visual references, such as clouds or terrain, can cause SD. Whilst pilots can compensate by learning to fly using cockpit instruments, a malfunction such as a vacuum failure, in less than desirable visual meteorological conditions (VMC) can also cause SD, with the same lethal results.
While some pilots are introduced to the concepts of SD during their flight training, general aviation pilots still have misunderstandings about what it is and how to deal with it. There is a misconception that the majority of pilots who suffer SD are junior in their career. In reality, however, the pilots who are most at risk are those that are quite senior, with 10 years of experience and over 1500 hours in the cockpit(Newman, Physiology of Orientation, 2012, slide 37). The estimated career incidence of SD is 90 to
100%. It is thought that a pilot has either been disorientated, or is about to be (Newman, Physiology of
Orientation, 2012, slide 4).
Types of Spatial Disorientation
There are three different types of SD:
1. Unrecognised (Type I)
2. Recognised (Type II)
3. Incapacitating (Type III)
The type of SD which most commonly causes accidents is Unrecognised SD (Type I). It is particularly dangerous as the pilot is not aware that disorientation has occurred. Therefore, the pilot does not make any alterations to correct the situation and the aircraft crashes into terrain.
Recognised SD is the most common form experienced by pilots. Unlike Type I SD, a pilot is able to recognise that there is a problem. However, it is important to
DISORIENTATION
The Importance of Awareness in
Aviation
Shanal Perera
HES1915A - Human Performance and Limitations in Aviation
Introduction
One of general aviation 's biggest killers - Spatial Disorientation (SD). It is the inability to correctly interpret aircraft attitude, altitude or airspeed in relation to the Earth or other points of reference. Any condition that does not allow the pilot to maintain natural visual references, such as clouds or terrain, can cause SD. Whilst pilots can compensate by learning to fly using cockpit instruments, a malfunction such as a vacuum failure, in less than desirable visual meteorological conditions (VMC) can also cause SD, with the same lethal results.
While some pilots are introduced to the concepts of SD during their flight training, general aviation pilots still have misunderstandings about what it is and how to deal with it. There is a misconception that the majority of pilots who suffer SD are junior in their career. In reality, however, the pilots who are most at risk are those that are quite senior, with 10 years of experience and over 1500 hours in the cockpit(Newman, Physiology of Orientation, 2012, slide 37). The estimated career incidence of SD is 90 to
100%. It is thought that a pilot has either been disorientated, or is about to be (Newman, Physiology of
Orientation, 2012, slide 4).
Types of Spatial Disorientation
There are three different types of SD:
1. Unrecognised (Type I)
2. Recognised (Type II)
3. Incapacitating (Type III)
The type of SD which most commonly causes accidents is Unrecognised SD (Type I). It is particularly dangerous as the pilot is not aware that disorientation has occurred. Therefore, the pilot does not make any alterations to correct the situation and the aircraft crashes into terrain.
Recognised SD is the most common form experienced by pilots. Unlike Type I SD, a pilot is able to recognise that there is a problem. However, it is important to
References: AOPA Air Safety Foundation (2004), Safety Advisor Physiology No.1. "Spatial Disorientation. Confusion that kills" Benson, A. (1988a). Spatial disorientation – common illusions. In J. Ernsting & PKing (Eds.), Aviation medicine (pp Cameroon Civil Aviation Authority. (28 April 2010)."Technical Investigation into the Accident of the B737800 Registration 5Y-KYA Operated by Kenya Airways that Occurred the 5th of May 2007 in Douala". Page 57. Flight Safety Foundation (2009), FSF ALAR Briefing Note 5.3, "Visual Illusions" (pp 2-3) Holmes, S., Bunting, A., Brown, D., Hiatt, K., Braithwaite, M., & Harrigan, M Newman, D. (2012). Physiology of Orientation, Lecture 2 - HES1915A - Human Performance and Limitations in Aviation, Slide 4 Newman, D. (2012). Physiology of Orientation, Lecture 2 - HES1915A - Human Performance and Limitations in Aviation, Slide 37 Pan American World Airways, Inc., Boeing 707-321-B, N454PA, Pago Pago, American Samoa, January 30, 1974