System forecasts dangerous in-flight icing conditions

Aircraft could be safer thanks to a new computer-generated forecast that provides pilots with critical weather information on the likelihood of encountering dangerous in-flight icing conditions.

In-flight icing occurs when water droplets from clouds freeze on the surface of an aircraft. Such icing can increase drag and decrease lift, ultimately causing the pilot to lose control of the aircraft.

The Forecast Icing Product with Severity, or FIP-Severity, provides 12hr icing forecasts that are updated hourly for pilots, air-traffic controllers and other users of aviation weather information who plan their flight paths over the US.

It was developed by researchers at the US National Center for Atmospheric Research (NCAR), with funding from the Federal Aviation Administration.

’In-flight icing can create extremely dangerous conditions for pilots,’ said NCAR scientist Marcia Politovich, who leads in-flight icing research at NCAR. ’Recognising the potential for icing conditions to develop over time and the degree of severity are both crucial for planning safe flights.’

FIP-Severity will most benefit commuter and small aircraft, said Politovich. Such aircraft are more vulnerable to icing hazards because they cruise at lower, ice-prone altitudes, below 24,000ft. They also may lack mechanisms common on larger jets that prevent ice build-up, such as heated wing edges.

FIP-Severity is a computer-based forecast of the probability of icing based on an analysis of temperature and humidity data associated with clouds, which are the source of in-flight icing. The automated algorithm gathers real-time information from satellites, radars, weather models, surface stations and pilot reports, and determines the probability of encountering icing, its expected severity and the likelihood of large-droplet icing condition, which are particularly dangerous because they rapidly impede an aircraft’s aerodynamics.

The capability is an update to NCAR’s original Forecast Icing Product (FIP), which has been in operation for several years but only calculates an uncalibrated icing potential. The Current Icing Product (CIP) depicts severity and probability of an encounter with icing, but only for current conditions. Requests from users for more detailed information led to the development of FIP-Severity.