Cold Wx Ops

Question 1

What must the first officer do after normal preflight duties are complete during cold we ops?

Answer 1

Switch all pitot heaters on and verify all lights extinguish.

Question 2

What can you do if cowl valves remain illuminated bright when on ground after they have been selected on after start?

Answer 2

Switch APU bleed off, increase thrust slightly up to a maximum of 30%n1

Question 3

What is different about the before taxi procedure during cold we ops?

Answer 3

Flaps, cycle full 40 then back to up before selecting t/o flaps.
Flaps extension may be delayed if taxi route is over slush snow etc.

Question 4

What must be done prior to take off when OAT is 3’c or below?
How often?

Answer 4

Engine run every 30mins @ 70%n1 for 30secs.
Practically, look at doing it on line up just ask tower for extra 30secs on line up.
( during freezing rain 70%n1 for min 1sec @ 10min intervals is reqd).

Question 5

Where should flaps, trim and bleeds be set for de/anti-icing?

Answer 5

Flaps- up.
Trim- t/o postion i.e green band.
Bleeds- engines and APU off.

Question 6

What conditions are considered icing conditions?

Answer 6

Temp 10’c or below and visible moisture I.e rain snow etc fog with vis below 1600m.
And/or ice snow slush on the ground.