With due respect to fellow pilots on regional aircraft, could we not take common action to counter ice-related accidents? After more than 25 years of flying regional aircraft and with an interest in ice-related incidents, I am sorry to say that I fail to recognise a natural degree of alertness and vigilance among pilots when conditions change from light to moderate or severe atmospheric icing conditions. Ice build-up must raise pilots' alertness and be monitored as this is a genuine threat to safety.
A big culprit is the autopilot, which can hide aerodynamic behaviour during ice build-up and only hands the aircraft over to the pilot when it is probably too late to avoid a partial or full loss of control. Fly by hand and you feel the aerodynamic effect of ice building up.
Pilots should know their aircraft minimum safe clean speed in icing conditions and never go below this. Manufacturers conduct flight testing in ice-related scenarios and must provide the information needed to establish a safe margin to the contaminated wing stall characteristics. If the minimum safe speed cannot be maintained, there is only one option - descent.
Meteorology suggests that "pockets" of moderate to severe icing is of relatively narrow horizontal, as well as vertical extent, so a change of altitude and/or direction of flight can contribute in escaping the affected airspace.
Modern high performance aircraft are less forgiving to contamination and this must be countered with a higher degree of attention.
Capt Hans Ingolf Nielsen Soenderborg, Denmark
Source: Flight International
