Why do planes have to be ‘de-iced’? © BAE Systems

Why do planes have to be ‘de-iced’?

Failure to de-ice can be disastrous, even when they are designed to withstand extreme temperature differences.

Asked by: Dan Pycroft, Exeter

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Planes are designed to cope with extremes of temperature, allowing them to take off from searingly hot desert runways before cruising in the bitter -55°C cold of the stratosphere just minutes later. Yet even the most sophisticated aircraft can be put at risk by freezing conditions.

When ice builds up along the leading edges of the wings it changes their shape – and thus their ability to generate lift. Aircraft are fitted with de-icing systems, but in severe conditions even these can be inadequate, requiring the application of high-pressure blasts of antifreeze.

Failure to use them can be disastrous. In 1982, ice on the wings of a Boeing 737 taking off from Washington DC prevented it from climbing adequately. It crashed into the frozen Potomac River, killing 74 passengers and crew.


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