Anti-ice Flashcards
Describe the anti-ice system.
Nacelle and wing anti-icing is provided by distributing engine bleed air to the nacelle inlets and to the wing leading edges. Bleed air is not available for nacelle anti-icing if the engine bleed PRV is closed.
When is NAI required?
When icing conditions exist:
1. OAT 10C or below in visable moisture or
dew point spread < 3C, contaminated
taxiways or runways.
2. During descent even with SAT < -40*C for
engine flameout mitigation.
When is an engine runup required and what is the procedure for a 900 series (GE engines) aircraft?
An engine runup is required when NAI is required and OAT < 3*C.
Then procedure is runup the engine to a minimum of 60% N1 for approximately 30 sec at intervals no greater than 30 mins.
(PW engine is min 50% N1 for approx 1 sec at intervals no greater than 15 mins)
What is the indication(s) that NAI is operating?
Green NAI indication adjacent to the respective N1 indicator on the primary (upper) EICAS.
Will WAI operate on the ground?
No, on the ground the system is off and the WAI valves are closed.
Does the WAI operate in-flight with the LE flap extended?
Yes but is ineffective.
When are the pitot static and AOA probes heated?
When any engine is running.