by Technical, Programs and Evaluations Team, Standards Branch, Civil Aviation, Transport Canada
In support of Transportation Safety Board of Canada (TSB) Recommendation A18-02, below are just a few reminders with regard to aircraft operations during ground icing conditions.
This information is for all pilots who fly in our tricky climate. Transport Canada wishes to maintain a high level of awareness within the civil aviation community of the hazards of flying with ice or snow (contamination) adhering to the critical surfaces of an aircraft, and flying into icing conditions.
The cold weather is upon us and so is the season for de/anti-icing. Past incidents and research have demonstrated that even small amounts of contamination on an aircraft’s critical surfaces can have a very large effect on the aircraft’s performance and handling qualities. Contamination such as frost with thickness as small as 0.40 mm (1/64 in.) can disrupt air flow over the lift and control surfaces of an aircraft, potentially leading to increased drag, lift loss and impaired maneuverability. This is especially true during the takeoff and initial climb phases of flight.
Ice can also significantly increase aircraft weight, interfere with the movement of control surfaces, and prevent the functionality of critical aircraft sensors.
Remember: there is no such thing as an insignificant amount of contamination; it is imperative that takeoff not be attempted in any aircraft unless it has been determined that all critical surfaces of the aircraft are free from contamination. This requirement can be met if the pilot-in-command verifies or obtains verification from properly trained and qualified personnel that the aircraft is ready for flight.
Aircraft operating from smaller or remote aerodromes may be de/anti-iced by ground handling personnel or sometimes by the pilot using a de/anti-icing fluid applied with a pressure sprayer. Aircraft operators may be responsible for carrying the appropriate de/anti-icing equipment on board the aircraft or storing the equipment at the aerodromes.
The holdover times for SAE-qualified de/anti-icing fluids are obtainable in the Transport Canada holdover time (HOT) guidelines by visiting the Holdover time (HOT) guidelines for de-icing and anti-icing aircraft page or requesting a copy of the Winter 2021-2022 Holdover Time Guidelines by emailing firstname.lastname@example.org.
Adequate anti-icing fluid coverage is absolutely essential to ensure the expected holdover time (HOT) can be attained. It is imperative that the personnel applying fluids are properly trained to utilize consistent fluid application techniques.
If reliable holdover times are to be achieved, only fluids that are stored, dispensed, and applied in accordance with the manufacturers’ instructions can be used. These fluids have undergone laboratory testing and qualification to confirm aerodynamic acceptability.
Pilots should become familiar with the applicable Canadian Aviation Regulations (CARs) and Standard 622 of the General Operating and Flight Rules Standards (GOFRS)—Ground Icing Operations, as well as the procedures recommended by the aircraft manufacturer in the pilot operating handbook (POH), aircraft flight manual (AFM), maintenance manual and, where appropriate, the aircraft service manual. As well, they should comply with all company operations manual (COM) provisions. Ground de-icing and anti-icing procedures vary greatly depending primarily on aircraft type, the type of contamination accumulation on the aircraft, and the freezing point depressant (FPD) or de-/anti-icing fluid type.
TP 14052—Guidelines for Aircraft Ground Icing Operations contains information for aircraft in ground icing conditions, including details on application methods, liquid types, and more.