Icing Condition Flashcards
When to apply Ice shedding procedure?
Icing condition and the OAT is +1°C (A320=3°C) or less, or if significant engine vibration occurs (PRO-NOR-SOP-09 A)
What is icing condition?
1) When OAT (on ground and for take off), or the TAT ( in flight), is 10°C or below and there is visible moisture in the air (such as clouds, fog with visibility of 1sm (1600m) or less, rain, snow, sleet, ice crystals)
2) when the OAT on the ground and for takeoff is at or below 10 °C and operating on ramps, taxiways or runways where surface snow, standing water or slush may be ingested by the engines, or freeze on engines, nacelles or engine sensor probes. (LIM-ICE_RAIN)
How to do Ice Shedding? (A320)
Accelerate the engines to minimum 50% of N1 at intervals not greater than 15min. No requirement to maintain the high thrust setting.
Should be performed just before takeoff
During static runup, 61-74% N1 range should be avoided
Advise ATC of the runup requirement when reporting ready
(PRO-NOR-SOP-09A)
Taxi procedure in icing condition
Maintain the flaps retracted until aircraft reaches the holding point of the takeoff runway.
This action prevents contamination of the slats/fly mechanism (PRO-NOR-SOP-09 A)
Taxi speed should be limited to 10kt (FCTM-SQI-010 B)
When to apply Eng ANTI ICE ?
ENG ANTI ICE must be ON, during all ground and flight condition, when icing condition are expected with a TAT at, or below, 10°C (PRO-NOR-SOP-13 A)
Unless the SAT is below -40°C (PRO-NOR-SOP-14 A)
During descent, ENG ANTI ICE must be ON when icing conditions are encountered (PRO-NOR-SOP-16 )
ENGINE ANTI ICE must be ON during all ground and flight operations, when icing conditions exist, or are anticipated, except during climb and cruise when the SAT is below -40 °C. ENGINE ANTI ICE must be ON before and during a descent in icing conditions, even if the SAT is below -40 °C.(PRO-SUP-30 A to B)
ENG ANTI ICE consequence?
The FADAC automatically controls continuous ignition and selects a higher idle thrust which gives better protection against flame-out. The IGNITION memo appears on the ECAM
Reduces the descent path angle (when the engines are at idle). The pilot can compensate for this by increasing the descent speed, or by extending up to half speedbrakes. (PRO-NOR-SOP-16 A)
When to apply WING ANTI-ICE?
Switch the WING ANTI ICE pb-sw to ON, only in severe icing condition (PRO-NOR-SOP-18 B)
Used to prevent ice formation, or to remove ice accumulation from the wing leading edges.
Whenever there is an indication that airframe icing exists. This can be evidenced by ice accumulation on the visual ice indicator, or on the windshield wipers (PRO-SUP-30 A to B)
What is different in after landing procedure when conducting Approach in icing condition?
If the approach was made in icing condition, or if the runway was contaminated with slush or snow, do not retract the flaps and slats until after engine shutdown and after the ground crew has confirmed that flaps and slats are clear of obstructing ice (PRO-NOR-SOP-21 A)
What is visible moisture?
Such as clouds, fog with visibility of 1 SM or less, rain, snow, sleet or ice crystals (LIM-ICE_RAIN P 1/2)
Icing condition pre-caution? I.e. Holding?
Extended flight, in icing conditions with the slats extended, should be avoided. (PRO-SUP-30 B to E)
Holding in Icing condition, maintain the clean configuration whenever possible. Use of engine anti-ice and total anti-ice increase fuel consumption
A320 engine anti ice +3.5% total anti ice + 5.5%
A321 engine anti ice +3% total anti ice + 6%
(FCTM-SI-010 B)
What is severe ice accretion?
Icing condition are severe when there is approximately 5mm of ice accretion on the airframe (PRO-SUP-30 B to E)
Runway contamination definition? What is damp/wet/standing water?
Damp - when the surface is not dry, but when the water on it does not give it a Shing appearance
Wet - when the surface has a shiny appearance due to a thin layer of water. When this layer does not exceed 3mm depth, no substantial risk of hydroplanning .
Standing water - by heavy rainfall and/or insufficient runway drainage with a depth of more than 3mm.
(PER-TOF-CTA-20 A)
When or how to turn on PROBE/WINDOW HEAT?
Cockpit preparation is completed
APU is started and air conditioning is on
ICE/SNOW is removed from windshield/upper cockpit fuselage
Then turn on the PROBE/WINDOW HEAT
*with ice or snow accumulated on the windshield/upper cockpit fuselage, and if the PROBE/WINDOW heat HEAT pub is turned on, melted snow running down from the cockpit windows could re-freeze on the fuselage area below, when the temperature is very low. This could create ice build up on the forward fuselage that could possibly disturb the airflow around the static/pitot/AOA probes.
(PRO-SUP-91 A to B)
After landing taxi in icing condition
To avoid damage on the slats/flaps mechanism, do not retract slats/flaps.
After engine shutdown, make a visual inspection to determine that the slats/flaps mechanism is free of contamination. Then follow PRO-SUP-91-50 A to B
Contaminated runway take off thrust setting?
MAX TO (PRO-SUP-91-50 B to C) FLEX thrust is prohibited (FCTM-SI-010 B)
What if FAULT light(s) remain ON after select ENG ANTI ICE?
Increase N2 on the associated engine by about 5%. When the valves open, retard the thrust levers to IDLE
What system is affected in cold weather?
EFIS/ECAM (when the cockpit temperature is very low)
The IRS alignment (may take longer than usual, up to 15min)
(FCTM-SI-010 A to B)
When is start of Hold over time (HOT)?
In one step, HOT starts for the beginning of the application of the fluid
In two steps, HOT starts from the beginning of the application of the second fluid
(FCTm-SI-010 B)
When is Antiskid deactivate?
At taxi speed below 20kts (FCTm-SI-010 B)
10kt (A330)
