DE-ICING AND ANTI-ICING AIRCRAFT

De-icing and anti-icing regulations

There are strict regulations in Canada governing the removal of ice, frost and snow (de-icing) and preventing their accumulation on aircraft (anti-icing) prior to departure. The Canadian Aviation Regulations prohibit persons from conducting or attempting to conduct a take-off in an aircraft that has frost, ice or snow adhering to any of its critical surfaces such as wings and propellers.

Air operators are responsible for having de-icing and anti-icing procedures in place to comply with Canadian Aviation Regulations. An inspection by company personnel or the pilot must be conducted immediately prior to take-off to make sure that no frost, ice or snow is present. Transport Canada enforces its de-icing and anti-icing regulations through a number of means, including a comprehensive monitoring, inspections and audits program.

The importance of de-icing aircraft

Frost, ice or snow on critical surfaces of an aircraft such a wings, propellers and stabilizers can have a significant impact on the operation of an aircraft. The aircraft can be affected in two ways.

1. The additional weight of the ice or snow adds to the total weight of the aircraft, increasing the lift required for the aircraft to take off.
2. The formation of frost, ice or snow also changes the airflow over the wing, reducing the overall lift a wing can produce.

This combination of reduced lift and increased weight can have crucial safety consequences even with small amounts of ice or snow.

De-icing aircraft

During flight operations under icy conditions, any frost, snow or ice on a critical surface of an aircraft must be removed prior to departure. This is normally done through the application of a de-icing fluid that melts the ice and removes it from the aircraft. In addition, an ice-preventive agent (anti-icing fluid) may be applied to critical surfaces prior to take-off, to prevent the accumulation of ice on critical surfaces. Aircraft that are approved for flight into known icing conditions are equipped with devices that, while the aircraft is in flight, either break up and remove ice on critical surfaces (de-ice boots) or prevent the accumulation of ice on critical surfaces (heated wing leading edge devices).

Large aircraft operating from major airports such as Toronto, Montreal, Vancouver, Calgary and Halifax are de-iced and anti-iced immediately prior to take-off at a central de-icing facility located on the airport. These facilities are normally operated by de-icing service providers.

Aircraft operating from smaller regional airports are generally de-iced by company personnel, or in some cases directly by the pilot of the aircraft, using a pressure sprayer containing an approved de-icing fluid. Aircraft must be de-iced shortly prior to take-off. When operating under icing conditions from sites not equipped with a central de-icing facility, aircraft operators are responsible for carrying the appropriate anti-icing and de-icing equipment on board the aircraft or store the equipment at the airport. If conditions are too severe, pilots are required not to attempt a take-off.

Research and development

Transport Canada has an extensive research program dealing with a wide range of projects including de-icing and in-flight icing hazards. Transport Canada also participates actively in several Canadian and international committees working to further improve de-icing and anti-icing products and procedures.

For instance, Transport Canada is one of many partners in the Alliance Icing Research Study project led by the National Research Council Institute for Aerospace Research, Environment Canada's Meteorological Service of Canada and NASA's Glenn Research Centre. The project is examining technology designed to detect aircraft icing on the ground and in the air. 

Transport Canada continues to raise awareness within the civil aviation community on the hazards of flying with ice and snow adhering to aircraft wings and on flying into icy conditions. Awareness is raised through products such as videos, safety seminars and articles in aviation safety publications.

For more information on de-icing or anti-acing visit Ground Icing Operations Standards.

January 2004