It is important that flight crew are aware of the extra considerations needed when preparing and planning for flight.
The YouTube link above gives an interesting overview of the effects on Propellor driven aeroplanes / Icing induced stalls
The wings of an aeroplane are said to be “cold-soaked” when they contain very cold fuel as a result of having just landed after a flight at high altitude or from having been re-fuelled with very cold fuel. Whenever precipitation falls on a cold-soaked aeroplane when on the ground, clear icing may occur. Even in ambient temperatures between -2 C and +15 C (28 °F and 59 °F), ice or frost can form in the presence of visible moisture or high humidity if the aeroplane structure remains at 0 C (32 °F) or below. Clear ice is very difficult to be detected visually and may break loose during or after takeoff.
The following factors contribute to cold-soaking: temperature and quantity of fuel in fuel cells, type and location of fuel cells, length of time at high altitude flights, temperature of re-fuelled fuel and time since re-fuelling.
Due to their properties, Type I fluids form a thin liquid wetting film, which provides limited holdover time, especially in conditions of freezing precipitation. With this type of fluid no additional holdover time would be provided by increasing the concentration of the fluid in the fluid/water mixture.
With a one-step de-icing/anti-icing the holdover time begins at the start of the treatment and with a two-step de-icing/anti-icing at the start of the second step (anti-icing)
The table opposite is extracted from the FAA document ' HOLDOVER TIME GUIDELINES'. The times given give an indication as to the time frame of protection that could reasonably be expected under conditions of precipitation. However, due to the many variables that can influence holdover time, these times should not be considered as minimums or maximums as the actual time of protection may be extended or reduced, depending upon the particular conditions existing at the time.
For a more detailed description of this procedure please consult your Operations Manual.
This pre-step process may be performed with various means (e.g., brooms, forced air, heat, heated water, and heated fluids with negative buffer freezing point). If the pre-step procedure is used, make sure that the subsequent de-icing process removes all frozen contamination including the contamination that may have formed on surfaces and or in cavities due to the pre-step process.
After this check has confirmed that the treated areas are clean, the following statement shall be given to the Commander: “Local Area De-icing only. Holdover times do not apply”
Use a fluid/water mixture with a higher concentration of glycol than is usually required by the OAT to prevent re-freezing.
No holdover times apply to underwing treatments.
For light deposits of both wet and dry snow, similar procedures as for frost removal may be adopted.
aircraft manufacturer's instructions.
spray from the leading edge to the trailing edge. Do not spray from the rear. Start at the highest point of the surfaces and work to the lowest parts, i.e. on most aeroplanes start at the wing tip and work towards the wing root.