Chapter 4 - Preventative Measures and Deicing Procedures

Forced Air Deicing

95.  Airlines have shown increased interest in the use of forced air deicing to blow frozen contaminants off an aircraft surface, corresponding to the development by several manufacturers of forced air systems mounted on conventional deicing vehicles.

96.  Some forced air deicing systems use high-pressure air or an air/fluid mix, while others are based on delivering large air volumes at low pressure. Some nozzle arrangements deliver air at a very high speed from the nozzle. A columnar air stream can be maintained over an extended distance to lengthen the effective reach of the high-speed air stream. Other designs demonstrate a very rapid decrease in speed of the air stream after it exits the nozzle. The air stream exiting the nozzle may be hotter than the ambient air because of the heat of compression.

97.  Because the use of forced air systems is a relatively new process, no firm recommendations on operational use of those tested systems can be made. Some operators have been authorized to utilize forced air deicing to remove dry snow.

98.  The use of forced air to remove contaminants, particularly snow, is a maturing technology. The concerns regarding the effect of large quantities of deicing fluid on the environment, in particular, has resulted in renewed forced air research efforts in recent years.

99.  The results of the research are promising but as with any technology, there are compromises to be made when using forced air systems. Nonetheless, ongoing research is revealing that there is significant potential for forced air systems both in terms of economic savings and environmental relief. The use of Forced Air is subject to approval from aircraft manufacturer.

Note:  A subsequent inspection of the critical surfaces will be required after the use of Forced Air.