Winter Ops Flashcards
Clear icing Rime icing and Mixed icing temperatures.
Clear icing: Appears between 2 and -10 degrees.
Rime icing: Appears between -10 to -15 degrees
Mixed icing: Appears between -15 and -20 degrees
Before de icing
Notify dispatcher as soon as you know you need to de-ice.
Remember to brief the crew and do a PA to the passengers that we will be deicing. If there is some fluid in the vent then we may get vapour in the cabin.
Also mention of engine ice shedding procedures expected or need to turn off air on during de icing procedure.
When applying cold weather corrections (Temp below 0 degrees)
Apply changes to MDA, crossing altitudes and altitude constraints.
Rank based Cross wind limitations
FO 3 Stripes: 30kts
FO 3 stripes RF: 25kts
FO 2 stripes: 25kts (not permitted to handle for take off or landing if W/S is reported)
FO 2 stripes RF: 20kts
Also not permitted to handle for take off or landing if W/S is reported. TW is greater than 5 kts. If vis is less than 800m or if runway is contaminated.
When operating into a cat C aerodrome training must be completed
Every 12 months if an approach hasnt been flown.
Icing conditions exist when
Temp is 10 degrees C or below and there is standing water, precipitation or vis is below 1600m
Freezing conditions exist when
Temp is below 3 degrees and there is standing water, precipitation or vis is below 1600m
SNOWTAM decoder can be found
On the EFB under flightman.
Position in the deicing queue in dublin can be found
On the portal.
If the APU is unserviceable and remote deicing is required.
Remote de icing may not be possible as in some cases the engines need to be shut down to protect personnel. Ops controller to be contacted in this case or if contaminated runway/LVPs are in operation and aircraft has inop essential equipment.
If the RTOW is limited in the case of the take off runway.
Load control need to be informed.
Engine fan blade icing check during walk around
Most likely to form on the inner part of the blades at low RPM.
Must check the blades are free and spinning. In the case of the NEO (Leap 1A engines) use the spinner to avoid damage to the blades.
Ice shedding procedures are to be carried out whenever
Icing induced vibrations occur or when engine operating in freezing conditions (3 degrees or below as per the FCOM) for more than 30 mins.
Or if in FRDZ FRRA FRFG +SN the max time between ice sheds is to be 10 mins.
The taxi in time from the previous sector is to be taken into account.
Must also be performed in the runway prior to take off.
Ice shedding procedure
To be found in the FCOM
Carried out every 30 mins in freezing conditions, every 10 in FRDZ FRRA FRFG or +SN, or whenever suspected. Taxi in time from previous sector to be included. Let passengers know if you suspect you need to do it.
Check ground surface conditions and surrounding area.
Inform ATC
Park brake: On
THR Levers: 60% N1 for 30 seconds (not limited if FRDZ FRRA FRFG or +SN)
THR Levers: To idle.
On runway braking can be done with pedals.
If surrounding or ground conditions don’t allow for 60% then should be high as possible.
Obviously stop immediately if aircraft starts moving
Rolling take off not to be performed.
If high engine vibration
If the engine vibration is above 5.7% N1 or 5.6% N2. In flight.
If icing suspected cause
Auto thrust off.
One engine at a time Idle then increase N1 to 80%
If engine anti ice is off switch it on one engine at a time at idle thrust with 30 seconds in between engine.
If icing not suspected reduce the engine thrust to below the vibration threshold. If this does not work this may suggest another problem with the engine.
Contaminated runway definition.
A contaminated runway is a runway covered with a contaminant with a depth greater than 3mm (1/8inch). Usually needs 25% contaminant but varies from country to country.
Contaminants can be Slush, Water, Wet or Dry Snow.
Hard contaminants
Only reduce surface friction
Compacted snow
Cold/dry ice
Wet ice
Fluid contaminants reduce friction and can cause hydro planing and precipitation drag. Fluid contaminants are
Water
Slush
Dry snow
Wet snow
Take off on contaminated runways.
Flex Take off is not permitted.
Take off on contaminated runways.
Flex Take off is not permitted.
Dispatch from a runway covered in wet ice is not permitted.