A volcano eruption in Eyjafjallajoekull, Iceland threw up a huge cloud of ash that stretched over the United Kingdom and parts of Norway, Sweden, Denmark and Finland. Thousands of flights were cancelled. The reason is that aircraft crashes can happen when airplanes fly through the cloud of volcano ash, which contains tiny particles of rock, glass and sand, and can damage aircraft engines.
How Does Volcano Ash Cause Aircraft Engine Failure?
Several factors combine to make some volcanic eruptions a danger to aircraft. The first is that the particles in volcanic ash are composed of hard materials, such as rock, glass and sand. The second factor is that when these particles are ejected high enough, they may be picked up by the high winds that can disperse them over large distances. A third factor is that the dust plume is not dense enough to be easily seen by airline pilots, but it is dense enough to cause severe damage to the engines, which may cut out and fail. Failure happens when the fine dust particles block up the air vents.
Indonesian Eruption at Mount Galunggung - BA Flight 009
Also known as the "Jakarta Incident" or the "Speedbird 9", this event happened on 24th June, 1982. The British Airways (BA) 747 jet was flying from London, Heathrow, to Auckland, new Zealand. As it flew over the Indian ocean, it flew into a high plume from ash from Mount Gulanggung , Indonesia. The pilot noticed an effect on the windscreen, but the weather radar showed clear skies. One by one, all four engines failed on the aircraft. The aircraft lost height as it glided, but eventually all four engines started to work again, as the aircraft was clear of the ash cloud.
On July 13th, almost three weeks after the BA flight 9 incident, a Singapore Airlines 747 jet had three of the four engines shut down in the same area.
Alaska Eruption at Redoubt Volcano - KLM Flight 867
In this case, the aircraft dropped from 25,000 feet to just 12,000 feet when all four of the engines cut out, on the Boeing 747. The incident happened when the jet flew through a cloud of high level ash from Redoubt volcano, Alaska. The pilot and crew were eventually able to restart two of the four engines, which was enough to keep the plane airborne long enough to land at Anchorage, Alaska. None of the passengers or crew were hurt. A contributing factor in this case was the height of the volcano, at over 10,000 feet.
Pilots also recorded high-altitude dust clouds from the Kasatochi volcano in Alaska, on 7th August, 2008.
Volcano Ash Effect On Airplanes Summary
There are at least three proven incidents of volcano ash causing airplane engines to cut out. In all incidents to date, the engines were able to start again, but the effect of high altitude dust particles on aircraft engines means that flights in the vicinity need to be canceled.
The eruption of the Eyjafjallajoekull volcano, Iceland, caused the cancellation of most European filghts, both scheduled and private flights, in mid April 2010.
References For Volcano Ash Effects on Aircraft
The information contained in this article can be found in several pages of www.bbc.co.uk, as well as "All Four Engines Have Failed", by Betty Tootell, one of the passengers on BA flight 009. Information on jet engines and how they work was taken from " Jet Engines: Fundamentals of Theory, Design, and Operation " (Hunecke, K., Motorbooks International, 2003). More information about extreme weather effects may be found in " 21st Century Image Guide to Severe Weather and Storms: Volcanoes, Volcanic Eruptions, and Ash Clouds ¿ JPG and PDF Images from National Oceanic and Atmospheric Administration (NOAA) Meteorology Satellites (CD-ROM) "
Martin Bell - Martin holds a B.Sc. degree in chemical engineering, and an M.Sc. degree in electronics and computing. He has spent more than 25 years ...
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