because the airplane stalls at higher-than-published speeds  with ice accumulation. On final approach for landing,  increased airspeed must be maintained to compensate for  this increased stall speed. After touchdown with heavy ice  accumulation, landing distances may be as much as twice the  normal distance due to the increased landing speeds. In this  chapter, ice prevention and ice elimination using pneumatic  pressure, application of heat, and the application of fluid is  discussed. modern aircraft, many of these systems are automatically  controlled by the ice detection system and onboard computers. Ice can be detected visually, but most modern aircraft have  one or more ice detector sensors that warn the flight crew of  icing conditions. An annunciator light comes on to alert the  flight crew. In some aircraft models, multiple ice detectors  are used, and the ice detection system automatically turns  on the WAI systems when icing is detected.  [Figure 15-4]  The ice and rain protection systems used on aircraft keep ice  from forming on the following airplane components: Several means to prevent or control ice formation are used  in aircraft today:  Equipment is designed for anti-icing or for deicing. Anti-icing  equipment is turned on before entering icing conditions and  is designed to prevent ice from forming. A surface may be  anti-iced by keeping it dry, by heating to a temperature that  evaporates water upon impingement, or by heating the surface  just enough to prevent freezing, maintaining it running wet.  Figure 15-3  gives an overview of ice and rain protection  systems installed in a large transport category aircraft. In  15-3 Figure 15-3.  Ice and rain protection systems. Ice Detector System Ice Prevention 1. Heating surfaces with hot air  2. Heating by electrical elements  3. Breaking up ice formations, usually by inflatable boots 4. Chemical application  •  Wing leading edges •  Horizontal and vertical stabilizer leading edges •  Engine cowl leading edges • Propellers •  Propeller spinner •  Air data probes •  Flight deck windows •  Water and waste system lines and drains • Antenna Ice and rain protection Wing anti-ice Ice detection Waste tank rinse fitting heater Waste drain line heat Drain mast heater Gray water  drain line  heater Water tank drain heater Water supply inline heater Windows Hydrophobic coating Hydrophobic coating Flight compartment window anti-ice Windshield wiper system Pitot probe heat Angle of attack sensor heat Total air temperature probe heat Engine probe heat Air data sensor heat Drain and water line heating Engine anti-ice