Aircraft Icing

Icing refers to atmospheric water droplets that are often defined as supercooled (< 0 °C), which freeze upon contact with a surface. Icing intensity is classified from trace to severe and icing types are rime, clear, and mixed ice. Icing can occur before and during the flight, greatly compromising the ability of the aircraft to operate safely. These details will be discussed in a future lesson. For now however, it is vital to understand that all critical surfaces such as wings, control surfaces, rotors, propellers, and horizontal and vertical stabilizers should all be confirmed clear of contamination prior to takeoff, regardless of whether or not a particular aircraft is certified to fly into icing conditions.

No person shall conduct or attempt to conduct a take-off in an aircraft that has frost, ice or snow adhering to any of its critical surfaces.

In very few cases – usually reserved for larger transport category aircraft – takeoff in an aircraft that has frost caused by cold-soaked fuel adhering to the underside or upper side, or both, of its wings is permitted if the takeoff is conducted in accordance with the aircraft manufacturer’s instructions. It is important to remember that this is only allowed because the manufacture has proven, through a vigorous testing and certification process that safety is not compromised despite the presence of frost cause by cold-soaked fuel.

Some aircraft are equipped and certified to operate in icing conditions, however some additional precautions are required. Where conditions are such that frost, ice or snow may reasonably be expected to adhere to the aircraft, no person shall conduct or attempt to conduct a take-off in an aircraft unless:

The aircraft has been inspected immediately prior to take-off to determine whether any frost, ice or snow is adhering to any of its critical surfaces.
The inspection must be done by the pilot-in-command, the pilot-in-command’s delegate or any other properly trained individual

Notifying the Pilot-in-Command

Where, before commencing takeoff, a crew member of an aircraft observes that there is frost, ice or snow adhering to the wings of the aircraft, the crew member shall immediately report that observation to the pilot-in-command, and the pilot-in-command or a flight crew member designated by the pilot-in-command shall inspect the wings of the aircraft before takeoff.

Passenger Announcement

Before an aircraft is de-iced or anti-iced, the pilot-in-command of the aircraft shall ensure that the crew members and passengers are informed of the decision to do so.