Whiteout
Whiteout is a weather condition that causes disorientation and low visibility by snow, overcast cloud and fog. Basically, the whiteout in aviation occurs when the pilots cannot see the visible horizon because of the terrain covered with snow in the white sky. Also, blowing snow may lead to the whiteout due to reduced visibility.
Types of Whiteout
There are several types of whiteout:
- Blizzard: the snow blown by the wind may make it difficult for the pilots to see far distances.
- Snowfall: the amount of snow falling from the sky may reduce the visibility and confuse pilots to clarify the objects.
- Clear air: in the clear air when it is not snowing, the overcast cloud may make it difficult to identify the horizon. Visual illusion may happen when the background is covered with snow, so that the snow surface cannot be seen easily from flying altitudes.
Prevention
The incident/accident due to whiteout situation can be prevented by pilot awareness. Pilots experience and confidence in controlling aircraft under whiteout circumstances can be achieved by appropriate training and risk assessments. The pilots should determine the potential of whiteout whereas the crews should inform the pilots of any sudden changes in weather (clouds or snow).
Solutions
- Instrument Landing System (ILS): an ILS is a ground-based instrument approach system that provides guidance to approaching and landing aircraft. A combination of radio signals and lighting system give safe landings in instrumental meteorological conditions (IMC) such as reduced visibility due to fog, rain or snow.
- Global Positioning System (GPS): a GPS system increases the safety and efficiency of flights. The modernised system also provides safe navigation services from departure, en-route, arrival as well as airport navigation. The improved GPS contains approaches to airports, increasing operational safety especially in poor visibility conditions.
Accidents
- Berling Air Cessna 208B Grand Caravan &
- Baker Aviation Cessna 208 Caravan I
The pilots of both two flights continued Visual Flight Rules (VFR) flights in the instrumental meteorological conditions. Then the pilots failed to maintain cautious altitude from the ground and crashed on the snow-covered terrain during final approach.
References
1. Krause, S. S. (2003). Aircraft Safety: Accident Investigations, Analyses & Applications. McGraw-Hill Publishing, the United States of America.
2. Rash, C. E. (2006). Flying. Flightsafety. Retrieved on 29 September 2009 from http://www.flightsafety.org/asw/dec06/asw_dec06_p44-46.pdf.
3. Wikipedia (2009). Instrument Landing System. Retrieved on 30 September 2009 from http://en.wikipedia.org/Instrument_landing_system.
4. Wikipedia (2009). Whiteout (weather). Retrieved on 27 September 2009 from http://en.wikipedia.org/wiki/Whiteout_(weather).