NTSB INVESTIGATING LOSS OF ENGINE POWER

OPERATING AIRCRAFT IN ICING CONDITIONS

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                        NTSB PRESS RELEASE
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National Transportation Safety Board

Washington, DC 20594

 

FOR IMMEDIATE RELEASE: December 18, 2008 

SB-08-58

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Washington, DC - The National Transportation Safety Board

issued a Safety Alert titled "Activate Leading-Edge Deice

Boots As Soon As Airplanes Enter Icing Conditions." 

 

"This Safety Alert, directed to the pilot community, is

intended to increase the visibility of airplane icing issues

and address procedures taught regarding the accumulation of

ice before activating deice boots," said NTSB Acting

Chairman Mark V. Rosenker.

 

Some of the highlights of the newly issued Safety Alert,

which was approved by all five Board Members, are:

*     noting that as little as 1/4 inch of ice can be deadly;

*     as little as 1/4 inch of leading edge ice can increase

the stall speed 25 to 40 knots; and

*     early activation of the deice boots limits the effects

of leading-edge ice and improves the operating safety

margin.

 

The Safety Alert states that leading-edge deice boots should

be activated as soon as icing is encountered, unless the

aircraft flight manual or the pilot's operating handbook

specifically directs not to activate them. 

 

In the Alert, pilots are instructed to maintain extremely

careful vigilance of airspeed and any unusual handling

qualities if the aircraft manual or the pilot's operating

handbook allows for an accumulation of ice before activating

the deice boots, and to turn off or limit the use of the

autopilot in order to better "feel" changes in the handling

qualities of the airplane.

 

"When followed, this Safety Alert will create a safer

environment for pilots flying in icing conditions," Rosenker

stated. 

This Safety Alert can be viewed at: http://ntsb.gov/alerts/SA_006.pdf 

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