M717 From United States of America, joined Dec 2002, 608 posts, RR: 4
Reply 1, posted (12 years 2 weeks 1 day 23 hours ago) and read 1786 times:
"Commercial A/C" covers a very broad range of equipment. As a general statement, most transport jet aircraft (B-737, 757, DC-9, A-320, etc.) use heated surfaces. On the other hand, many turboprop aircraft (DHC-8, ATR-42/72, SF-340, SA-227, BE-1900, etc.) have de-ice boots.
KAUSpilot From United States of America, joined Jan 2002, 1975 posts, RR: 30
Reply 2, posted (12 years 2 weeks 1 day 23 hours ago) and read 1797 times:
Both. Some aircraft (mostly smaller turbine aircraft and piston aircraft) use pneumatic de-ice boots which expand and "knock off" layers of ice after they have built up on aircraft leading edge surfaces.
Other aircraft (larger jets) are equipped with a thermal leading edge anti-ice system. Here, hot, high-pressure engine bleed air is routed under leading edge surfaces to prevent the formation of ice. The main advantage of the thermal system is that it can be used in a preventive fashion, whereas it is usually inadvisable to active pneumatic boots until a pre-determined amount of ice has already built up on the aircraft. The disadvantages of thermal systems are that they use a good deal of engine power, because they draw off of air from the compressor sections of the engine, and they usually should not be used on the ground because warping of the aircraft metal can occur due to the relatively high temperatures encountered at ground level compared to cruising altitude.
Still other types of aircraft incorporate liquid ice protection (weeping wing). Basically, in these systems an anti-ice fluid is secreted through tiny pores in the wings. There are also electrically heated de-icing boots where are too energy demanding to use on large surfaces but are commonly found in use on propeller blades.