Ice and Rain Protection

Question 1

Which areas are protected by heat (air or electrical)

Answer 1

HOT AIR
‐ Three outboard leading-edge slats of each wing
‐ Engine air intakes

ELECTRICAL HEATING
‐ Flight compartment windows
‐ Sensors, pitot probes and static ports
‐ Waste-water drain mast

Question 2

Which wing surfaces are protected by Hot Air?

Answer 2

• outboard slats (3-4-5) of each wing

- Air is supplied through one valve in each wing

Question 3

What happens to anti-ice valves if electrical supply fails?

Answer 3

• Wing Anti-ice valves close

- Engine Anti-Ice Valves Open

Question 4

How are the engines protected from ice?

Answer 4

Each engine is protected independently through its own air bleed from the high pressure compressor

Question 5

When does probe/window heating come on?

Answer 5

‐ automatically on the ground (except TAT probes) when at least one engine is running, or when the aircraft is in flight
‐ manually, before engine start, when the flight crew switches ON the PROBE/WINDOW HEAT pushbutton switch

Question 6

How is Prob Heating controlled and monitored?

Answer 6

Three independent Probe Heat Computers (PHCs) automatically control and monitor:
‐ Captain probes
‐ F/O probes
‐ STBY probes

Question 7

Which probes are heated?

Answer 7

‐ Pitot probes
‐ Static ports
‐ Angle-Of-Attack (AOAs) probes
‐ Total Air Temperature (TAT) probes