Chapter 4 - Preventative Measures and Deicing Procedures

Hangars

1.  The best method of ensuring that an aircraft is clean of contamination is by preventing the contamination from collecting in the first place; that is, park the aircraft in a hanger. Availability of space, particularly for larger aircraft is a major obstacle with respect to the use of hangars on a routine basis.

2.  If precipitation is present, care must be taken to reduce the skin temperature to below freezing prior to taking the aircraft from the hanger. This can be accomplished by opening the hanger doors prior to rolling the aircraft out. This, of course, will impact the users of the hanger. Depending on the facility, it may be possible to apply anti-icing fluids prior to departing the hanger.

3.  Parking a fully or partially fuelled aircraft in a heated hangar presents special considerations. The temperature of the fuel will gradually rise towards the ambient temperature of the hangar. When the fuel is in contact with the upper surface of the wing, the wing surface will assume the temperature of the fuel; so cooling the wing surface by opening the hangar doors is less effective. This temperature effect will be present for an extended time period while the fuel cools once the aircraft is exposed to the outside temperature. When precipitation is present, the warm surface can cause snow and sleet to warm and stick to the wing or to melt. In this instance the application of deicing/anti-icing fluids may be the only effective solution. Possibly, under these circumstances, the aircraft should not be hangared with significant volumes of fuel in wing tanks.

4.  Once an aircraft is contaminated, if a heated hanger is available, the heat and shelter from the elements will help the removal of contamination. Unfortunately, this takes time but will reduce the amount of deicing fluid required.