Cold Weather Operations

Question 1

What is acceptable ice?

Answer 1

The aircraft must be free of all forms of ice with the exception of i) thin hoar frost on the fuselage provided the static vents are clear and ii) up to 3mm on underside of wing tank area. Ice ridges that have formed due to re-freezing are not acceptable.

Question 2

Define Icing Conditions

Answer 2

OAT at or below 10˚C and there is visible moisture present (including fog with visibility < 1,600m) or standing water, snow or slush on ground.

Question 3

When should engine runs be used? What are they?

Answer 3

When in icing conditions and OAT is ≥3˚C or if significant engine vibrations occur then

CEO: 50% N1 (no hold time) at intervals no > than 15mins. Plus a Static Run prior to takeoff.

NEO: 50% N1 for 5s at intervals not > than 60mins. Plus a Static Run prior to takeoff.

After static run, thrust must be returned to idle.

Question 4

What should you do if the EAI valves don’t open?

Answer 4

Add 5% N2

Question 5

What is a contaminated runway?

Answer 5

A runway is CONTAMINATED when a SIGNIFICANT PORTION* of it’s surface is covered with;

• a layer of fluid contaminant not considered thin (3mm Dry Snow, Wet Snow, Standing Water or Slush)
• a hard contaminant (Compacted snow, Ice and wet ice)

*depending on applicable regulation

Question 6

What is the maximum landing category on a contaminated runway?

Answer 6

CAT 3A

Question 7

What what is the effect of contamination on XWC?

Answer 7

Reduces from 38kts towards 15kts.

Question 8

What is the definition of Severe Ice Accretion?

Answer 8

The airframe is covered is covered in ice approximately 5mm thick or more.

Question 9

What is the minimum speed with Ice Accretion?

Answer 9

Clean, F1, F2 or F3; VLS + 10kts

FF; VLS + 5kts

If WAI not working then; VLS + 10kts