Ice Protection Flashcards
When is cowl anti-ice required on the ground? (AFM Limitations)
When OAT is +10°C or below and visible moisture is present; or while operating on
contaminated taxiways/runways
When is wing anti-ice required on the ground? (AFM Limitations)
Must be ON for takeoff when OAT is +5°C or below and visible moisture is present, or operating
on contaminated runways
What are the conditions for in-flight icing operations? (AFM Limitations)
Visible moisture and temperature at a TAT of 10°C or below, except when the SAT is -40°C or
below
What is the operating limitation while holding in icing conditions? (AFM Limitations)
Do not hold in icing with the slats extended
Ice protection is provided for which systems?
Wing leading edges
Engine cowls
Windshields & side windows
Air data smart probes and sensors (ADSPs)
Total air temperature (TAT) probes
Angle-of-attack (AOA) sensors
Enhanced vision system (EVS) window and fairing
When the does the cowl anti-ice operate when selected to AUTO?
When the ice detector system detects ice
When is the wing anti-ice system inhibited on takeoff if set to AUTO?
Up to 1,500ft or
2 minutes after the airspeed passes 60kt
Under what condition will the wing cross bleed valve automatically open?
WING XBLEED rotary switch is in AUTO and one system is not pressurized.
Note: this could be a valve failure or and inoperative engine
What is the purpose of the wing anti-ice cross bleed valve?
Allows both wing anti-ice systems to be supplied bleed air from a single engine
Which engine bleed source is used for cowl anti-ice?
7th Stage medium pressure (MP) of the high-pressure compressor (HPC)
The cowl anti-ice valve (CAIV) defaults to what position?
It is spring-loaded open; designed to open in the event of loss of electrical power
Why is it recommended to remove all pitot and AOA covers prior to starting the APU or connecting
external power?
All probe heaters are tested and powered when AC power is applied to the aircraft as part of the
built-in test
Note: When AC power is applied to the aircraft there is a continuity test of the heaters. This in
not enough voltage to generate the heat necessary to damage the pitot covers. When the first engine is started, the pitot heat is on full. Removing the covers before AC is applied is a convenience; the pilot may be outside already and doesn’t have to remember before the engine start.
When are the ADSP heaters automatically tested and operated?
All heaters are tested when AC power is initially applied
The system turns on automatically when one engine is running, or
Airspeed is greater than 50kt
When does automatic application of TAT heat occur?
Airplane is in flight, or
Airspeed greater than 50kt, or
RAT is deployed, and airspeed is greater than 120kt
