Aviation Maintenance: Ice and Rain Protection

Ice distorts the shape of the airfoil, reduces aerodynamic lift, and adds weight to the aircraft.

To illuminate an annunciator light in the flight deck and, on some aircraft, automatically turn on anti-icing systems.

Pitot tubes are heated by electric current flowing through heater elements built into them.

The windshield has an embedded heater element that uses electric current to keep ice from forming.

After ice has formed. When the boot inflates, it breaks the ice, and airflow over the airfoil blows it away.

From the discharge side of the air pump used to operate the gyro instruments.

A vacuum pump that uses engine oil to lubricate its steel vanes.

To remove lubricating oil from the discharge air before the air is used in the deicer boots.

By washing them with mild soap and water.

They are bonded to the surface with an adhesive. Older boots were attached with machine screws and Rivnuts.

The center tube inflates first, followed by the upper and lower tubes a specified number of seconds later.

Only when the windshield is wet with rain.

In the aircraft maintenance manual.

Turn it on for about a minute, then feel the pitot head during the walk-around to verify that it is warm.

In the illustrated parts manual for the aircraft.

A static system leak test must be performed and the results recorded in the aircraft maintenance records.

Briefly turn on the pitot heat system and observe an increased current indication on the ammeter.

A tripped circuit breaker or a broken wire to the electrical heating elements.

By observing an increased ammeter reading when the system is energized.

Rain can be blown away by a high-velocity blast of compressor bleed air or wiped away with electrically or hydraulically operated windshield wipers.

Running windshield wipers on a dry windshield can damage the windshield, and over-pressurizing deice boots with a ground test system can damage the boots. Follow the maintenance manual procedures whenever testing or servicing ice control systems.

Deicing fluids can be hazardous to health and the environment. Always follow the manufacturer's recommendations for handling and storage.

Incorrect cleaning materials can damage windshields and reduce visibility through the windshield. Follow the maintenance manual procedures for cleaning heated windshields.