Cold WX Ops

Question 1

What Icing conditions is take off prohibited in?

Answer 1

• Moderate and / or heavy freezing rain
• Heavy Snow +SN, Ice pellets PL, Hail GS. If for any reason a pre take off check cannot determine if frozen contaminants are adhering and / or that fluid failure has occurred.

Question 2

Explain how partial snow removal works on a runway?

Answer 2

• Cleared runway width may not be less than 30m
• runway may be cleared to width of less than 45m. This is not considered narrow unless limited by snowbanks.

Question 3

When is a runway contaminated?

Answer 3

• Runway contaminated when more than 25% of one third of the runway length and width being used is covered with:

Fluid contaminant greater than 3mm.
- Dry snow, Wet snow
- Standing water, Slush

Hard contaminant - Compacted Snow, Ice and wet ice.

Limitation: Captain & TOGA.

Question 4

Can frost be on the aeroplane?

Answer 4

Thin hoar frost is acceptable on the upper surface of fuselage, radome and engine exterior surfaces.

Surface features can be distinguished beneath it.

Underside of wing tank. Max layer of 3mm is acceptable.

Question 5

What to do if dispatch landing perf cannot be satisfied at destination?

Answer 5

Still permitted to go, provided two alternates are designated.

Question 6

Engine warm up times?

Answer 6

3min except for NEO which also needs oil temp above 19degrees C so might be longer.

Question 7

What are the Ice Shedding procedures?

Answer 7

Using brakes and when 3 degrees or less.

CEO: 70% N1 for 30 seconds at intervals not greater than 30min. Do prior to take off.

In freezing rain, drizzle, fog or heavy snow, do this every 10 minutes.

NEO: 50% N1 for 5 seconds at intervals not greater than 60min. Do prior to take off.

Question 8

Minimum speed with Ice Accretion?

Answer 8

Wing Anti Ice Operative:

Conf: Clean, 1, 2 or 3. = VLS +10
Conf: FUll VLS + 5

Wing anti Ice In-operative

VLS +10 / Green dot

Question 9

How and when to record icing conditions in the tech log?

Answer 9

Use for info section.

If taxiing in icing conditions with OAT 3 degrees or less.

Record taxi in time and log taxi time since last shedding if appropriate.

Question 10

What are the de-icing fluid colours?

Answer 10

Type 1 - Straw

Type II - Light Green

Type IV - Dark Green

Question 11

Cold weather temp limit in flight?

Answer 11

-70 degrees. Descend to increase temp.

Question 12

If ice or fluid (Type IV Thick stuff) on radome or flight deck windows, what do we do?

Answer 12

Use a diluted type 1 mixture to remove it.

Question 13

When operating a CEO aircraft in certain icing conditions on the ground, there is an enhanced ice shedding engine run up procedure. In what conditions is this enhanced procedure applicable and what is the procedure?

Answer 13

Freezing rain, freezing drizzle, freezing fog or heavy snow
In addition to standard 30 minute run ups, every 10 minutes, momentary run up to 70% N1

Question 14

When operating in icing conditions on the ground, what are the engine run up procedures?

Answer 14

CEO: Accelerate engines to approximately 70% N1 for 30 seconds at intervals not greater than 30 minutes
NEO: Accelerate engines to approximately 50% N1 for 5 seconds at intervals not greater than 60 minutes
For both engine types, engine acceleration should be performed just before takeoff.

Question 15

In event of frost formation on one or several areas of the wing, can localised deicing be applied to only the affected areas?

Answer 15

Yes Ensure both wings receive symmetrical treatment even if frost formation does not affect both wings symmetrically

Question 16

A thin layer of frost is permitted on the airframe in a specific area. What area is this and what is the maximum permitted depth?

Answer 16

Underside wing tank areas
3mm
Additionally thin hoar frost permitted on upper fuselage, radome, engine exterior

Question 17

In the three following scenarios, what is the minimum airspeed with ice accretion (defined by ice on the visual indicator)
1) Wing anti ice operative, CONF Clean, 1, 2 or 3;
2) Wing anti ice operative, CONF Full;
3) Wing anti ice not operative, all CONF

Answer 17

1) VLS + 10kt
2) VLS + 5kt
3) VLS + 10kt/GREEN DOT

Question 18

What’s the definition of active frost?

Answer 18

A condition when frost is forming and occurs when Aeroplane Surface Temperature is less than or equal to 0°C AND less than or equal to the dew point

Question 19

How should Probe/Window heat be operated when on the ground in cold weather?

Answer 19

ON during Prelim Cockpit Prep
AUTO after first engine start (heating continues automatically)

Question 20

What do the colours in HOT signify?

Answer 20

Colours relate to snowfall intensity derived from Snowfall Intensities as a Function of Prevailing Visibility table

Question 21

In a 2 step process when does HOT start?

Answer 21

Start of application of second fluid

Question 22

What are the key points related to Local Wing Frost Removal

Answer 22

Must be done symmetrically
No precipitation falling
On request of pilot only
No HOT applicable. Clean Aircraft concept instead

Question 23

Can you take off after HOT exceeded?

Answer 23

Yes, if pre-takeoff check conducted.
Pre take off check: failed fluid appears opaque; check both sides (wind affect one side more than the other); failure occurs leading/trailing edge first

Question 24

Considerations for taxiing after landing in cold weather conditions

Answer 24

If chance of ice accumulating in flap area, leave flaps out
Leave engine anti ice on until shutdown
Perform engine run ups as required
SE taxi permitted if taxiway not slippery & no chance of ice accumulation on Engine #2
To retract flaps after engine shut down - procedure in Cold Weather Quick Reference

Question 25

SNOWTAM max validity period

Answer 25

8 hours

Question 26

Runway Condition Report RCR format

Answer 26

ICAO; DDMMTT; RWY; RWYCC; % per 1/3; Depth per 1/3; Surface descriptor per 1/3
EDDM 011209 08L 3/3/3 100/100/100 04/04/04 WET SNOW/WET SNOW/WET SNOW

Question 27

What data do you use for contaminated runway performance? Take off, landing dispatch and landing in flight

Answer 27

Take off: Type & depth of contaminant, Runway Condition Determinator (Take Off)
Landing Dispatch: Type & depth of contaminant, Runway Condition Determinator (Landing Dispatch)
Landing In Flight: RCR and worst RWYCC contained in it. If non GRF format, use RCAM in QRH to get RWYCC

Question 28

When do you make low altitude low temp corrections? What altitudes are they applied to?

Answer 28

Surface temp -10°C or below
DA & MDA
NPA minimum altitudes after passing FAF
FAF, except baro-VNAV procedures with temp limit

Question 29

Contaminated Runway

Answer 29

A runway is contaminated when a significant portion of its surface is covered with: a layer of fluid contaminant not considered as thin OR a hard contaminant.
Significant portion: more than 25% of one third of runway surface area within the required length and width being used

Question 30

What runway cold weather conditions do not permit takeoff?

Answer 30

Wet ice
Water on top of compacted snow
Snow over ice

RWYCC 0

Question 31

Partial runway snow removal

Answer 31

Cleared/treated runway width - minimum 30m

Runways wider than 45m can be cleared to less than 45m. Not considered narrow runway unless limited by snow banks

Question 32

What are the operational restrictions of operating on contaminated taxiways/runways?

Answer 32

No single engine taxi
No flex take off
Captains only take off

Consider:
Full length take off
Not tankering