Anti-ice

Question 1

Describe the anti-ice system.

Answer 1

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.

Question 2

When is NAI required?

Answer 2

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.

Question 3

When is an engine runup required and what is the procedure for a 900 series (GE engines) aircraft?

Answer 3

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)

Question 4

What is the indication(s) that NAI is operating?

Answer 4

Green NAI indication adjacent to the respective N1 indicator on the primary (upper) EICAS.

Question 5

Will WAI operate on the ground?

Answer 5

No, on the ground the system is off and the WAI valves are closed.

Question 6

Does the WAI operate in-flight with the LE flap extended?

Answer 6

Yes but is ineffective.

Question 7

When are the pitot static and AOA probes heated?

Answer 7

When any engine is running.