Engine Anti-Ice System

STUDENT GUIDE FOR T-1A AIRCRAFT SYSTEMS

CHAPTER EIGHT

Manual Deice Operation

Should a problem with the normal anti-ice/deice systems develop, a manual backup system is

provided. The deice backup system is controlled by a red cover guarded toggle type switch,

placarded H STAB DEICE BACK UP on the overhead panel. To activate the backup system,

the red cover guard safety wire is broken, the red cover guard is lifted, and the toggle switch is

pushed forward to place it in the MANUAL switch position momentarily, then released. The

switch returns to the OFF position. This will start a deice cycle of 30 seconds.

805. ENGINE ANTI-ICE SYSTEM

Each engine is protected by an anti-ice system utilizing high-pressure compressor bleed air. A

small amount of the high compressor turbine air is continuously directed to the inlet cone and to

the T-1A temperature probe.

806. AIR INLET AND ENGINE STATOR ANTI-ICE

An inlet bleed air temperature switch closes when the air temperature is below 120F, causing

the L ENG ICE TEMP LO or R ENG ICE TEMP LO annunciator on the main annunciator panel

to illuminate. The annunciator will extinguish when the temperature reaches 120F and the

valve opens.

807. AIR DATA SYSTEMS ANTI-ICING

The pitot static and AOA systems are protected from ice by electrical heating elements. The

design of the protective housing prevents icing from forming on the outside air temperature

probe.

Pitot Tube Heating System

An electrically heated pitot tube is located on each side of the aircraft nose. The pitot heating

system is monitored with a white operating light above each pitot heater switch. When

illuminated, the operating light indicates current flow to the heater. An amber caution light on

the main annunciator panel illuminates PITOT HT OFF if one or both pitot heat systems have

failed or have been turned off.

Static Port Anti-Ice System

Four electrically heated static ports are flush mounted on the forward fuselage of the aircraft, two

on each side. One static port serving the P instrument panel, and one serving the CP instrument

panel is located below the flight deck window on each side. White operating lights directly

above the respective rocker switches illuminate when current is flowing to the heater.

ANIT-ICE AND DEFOG SYSTEMS

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