Cold WX OPS Manual Q&A Flashcards
What is the rule of priority in case of discrepancies between manual ?
Wizz Air OM, Airbus Manual, Cold Wx Ops Manual (p.8)
What is the Cold Wx Ops Manual based on ?
Getting the grips with Cold Wx Ops AIRBUS (p.8)
What is the Pre Take-off Contamination Check, and is it allowed in Wizz Air?
It’s an external check of the contaminated aircraft surfaces in case expiry of HOT or any doubts in regards to effectiveness of anti-icing treatment. Not Authorised in Wizz Air Ops (p.10)
What is the generic meteorological conditions where Icing Condition may occur ?
From slightly positive temperature down to -40ºC, most likely around FL100 (p.12)
In addition to putting ENG ANTI ICE and WING ANTI ICE ON what else should the pilot keep an eye on?
Ice accretion rate and type of cloud (p.12)
When rapid icing in encountered in a Stratiform Cloud what will be the best course of action?
Moderate change of altitude to significantly reduce the rate of accretion (p.12)
What is best course of action if icing conditions are encountered during approach?
Keep high speed, delay flap extension, do not retract flaps after landing (p.12)
Why Type III fluid is not used in Wizz Air ?
Because is unsuitable for JET aircraft (p.13)
Are published HOT tables 100% reliable or other factors may influence their applicability ?
Severe weather, high wind velocity and jet blast will shorten the protection time (p.13)
What effects do water, slush and loose snow (fluid contaminants) have on Breaking and Accelerating performance on a contaminated runway ?
- reduce breaking efficiency and
- accelerating performance
plus possible - aquaplaning
- additional drag(p.13)
What effect does compacted snow and ice have on Breaking and Accelerating performance on a contaminated runway?
Such called Hard Contaminants only effect Braking Performance due to the reduction of friction coefficient (p.13)
When the total friction force is significantly reduced by the presence of a contaminant of the runway and with Crosswind conditions, the pilot may have to choose between braking and controlling the aircraft, is this true or false?
True (p.14)
The maximum crosswind landing for Automatic Landing is a limitation? True of False?
True (p.14)
What effect does the presence of a contaminant on the runway have in regard to accelerate-stop distance and accelerate-go distance ?
They both increase (p.15)
If a short runway is contaminated what flap setting should be used?
higher then usual always considering the second sector (p.15)
A normal size contaminated runway calls for higher or lower speeds ?
lower (p.15)
If the temperature is below ISA what is the True Altitude compare to Indicated Altitude?
below (p.16)
Saturation conditions may be exceeded by two process ?
lifting of warm air and night with clear sky (p.16)
What is the Kinetic Heating and how is it calculated?
is the increase in heat of the leading edge compared to the rest of the wing at a given speed (p.20)
What is the advantage of Kinetic Heating of the Leading Edge?
It prevents the leading edge from icing (p.20)
How is Kinetic Heating calculated ?
TAT - SAT (p.20)
At 250kt how much is KH (kinetic heating) ?
+10ºC (p.20)
Up to what temperature can KH (kinetic heating) prevent icing of the leading edge ?
- 10ºC (p.20)
What are some generic rules of thumb in regard to Icing?
- icing conditions are more frequent then actual aircraft icing in such conditions
- Increase of speed decreases the ice accretion
- If rapid ice accretion is met, moderate change of FL is usually enough (p.22)
How should ATC behave in case a pilot requests FL change due to icing ?
they must immediately accept such request (p.22)
Are aircraft certified to sustain icing in configurations with Slats and Flaps out?
NO, it is assumed that an aircraft will not stay long enough in such condition with such configuration (p.23)
What are the 3 principle methods of protecting airframe from ice accretion?
- Mechanical
- Electrical Heating
- Hot Bleed Air (p.23)
Hot Bleed Air is majorly used as a Anti-Ice can it be also used as De-ice?
yes but only for light ice accumulation (p.23)
Why is it that large aircraft are more resistant to icing then small aircraft ?
due to the size and thickness of their wings (p.23)
Why is Wing Anti Ice (WAI) inhibited on the ground ?
the heat created by this system is very high. It’s designed to prevent ice formation, and to melt ice if any, also to evaporate the water left from melting the ice. In flight, speed will cool down the leading edge once no ice is longer present, on the ground such heating at such low speed will cause damage to the slats. (p.24)
Why is Engine Anti Ice (NAI) not inhibited on the ground ?
differently from the wing anti ice the “sucking” effect of the engines create enough cooling for the engine nacelle heated by the NAI (p.24)
Which parts of the aircraft (A320) are electrically heated?
- aircraft sensors
- Static ports
- Pitot tubes
- TAT
- AOA probes
- Flight deck windows
- Waste-water drain masts are electrically anti iced (p.24)
Do the electrically heated parts of the aircraft (which fight agains icing) suffer from overheating on the ground, similarly to wing leading edge ?
yes, this is solved automatically by air/ground logic (p.24)
Is the RAT (Ram Air Turbine) protected by any anti-ice system?
RAT is driven by a two-blade propeller with a “self-shedding” design, which means that the centrifugal force will throw away any ice formation on the outer part of the propeller (p.24)
According to AFM and FCOM, in which weather conditions do they state that Icing Conditions maybe expected both on ground or for take off, and flight?
when OAT (ground and take off) or TAT (flight) is at or below 10ºC and there is visible moisture in the air (such as clouds, fog with visibility of 1000m or less, rain, snow, sleet, ice crystal) or on taxiways or runway with standing water, slush, ice or snow. (P.26) FCOM.LIM-ICE RAIN says 1600m or less (p.87)
Usually when SAT is below -40ºC event though in icing conditions the NAI is not longer necessary unless …?
when entering cumulonimbus clouds (p.26)
When does the FCOM suggest to activate WAI ON?
when there is indication of ice accumulation evident by ice build up on the windshield or the ice detector pin (p.26)
What type of conditions will lead to require de-icing of an aircraft?
- frost, ice snow or slush
- Temperature approaching zero or below zero
- Humid air above freezing getting in contact with cold aircraft surfaces (p.28)
What is Active Frost and what are the conditions for it to form?
- is when frost if forming
* Occurs when aircraft surface temperature is at or below 0ºC and at or below dew point (p.28)
What is the biggest danger of Clear Ice and the best way to detect it ?
very hard to be visually detected the best way is to check by hand touch (p.31)
Is it possible for Clear Ice to occur at ambient temperature of 15ºC and in what circumstances?
yes, as a result of rain or high humidity on cold soak wings (p.31)
What are the major weather conditions that cause Clear Ice ?
Large super cooled droplets of freezing fog, drizzle or rain, usually freezing at a slow rate (p.31)
Would you expect do find Clear Ice hidden under a layer of snow or slush on the wing?
Yes (p.31)
What is Cold Soak Effect?
The wings of an aircraft are said to be cold soaked when they contain very cold fuel as a result of having just landed after a flight at high altitude or having been refuelled with very cold fuel (p.31)
In what kind of ambient temperature can Cold Soak Effect occur and what about the wing temperature?
ambient temperature between-2ºC and +15ºC with the aircraft structure at 0ºC or below (p.31)
What is Frost/Hoar Frost and how is created?
- water vapour changing directly to ice on the form of frost
* When the temperature of aircraft surface and dew point are both below freezing (p.31)
What is Rime Ice and how is formed?
- whitish rough deposit of ice
* Formed by instantaneous freezing of small super-cooled water droplets (p.31)
What is Slush and how is created?
- water saturated with snow encountered at temperature around 5ºC.
- Defined as snow or ice reduced to a soft watery mixture (p.31)
Should you relay on someone else to have done the job unless clearly reported as having been done?
No, uncertainty should not be resolved with transferring responsibility (p.31)
What type of contamination is acceptable on an aircraft before take off?
- Thin Hoar Frost on the upper surface of the fuselage
* Maximum layer of 3 mm of Frost on the underside of the wing tank area (p.33)
Can you leave Dry Snow on an aircraft surfaces to be blown away during take off roll?
NO
Thin Hoar Frost is acceptable on the upper surface of the fuselage how do you recognise Thin Hoar Frost?
typically a white crystalline deposit, so thin that surface feature (lines and markings) can be distinguished (p.33)
Regarding to aircraft icing what are identified as Critical Surfaces of an aircraft?
- Leading edge
- Upper surface of the wings
- Vertical and horizontal stabiliser
- All control surfaces
- Slats and Flaps (p.34)
In what weather conditions on the ground is necessary to check for any ice build up behind the engines’ fan blades ?
Freezing fog (p.35)
What are the areas of a wing most vulnerable to Freezing ?
- the wing root area between the front and the rear spar
- Any part of the wing that contains unused fuel after the flight
- The areas where different wing structures are concentrates such as areas above the spars an the main landing gear doubler plate (p.36)
Is the de-icing anti-icing report part of the Air Worthiness of the aircraft?
Yes (p.38)
On who does the responsibility of accepting the performed de-icing anti-icing treatment lies on ?
the Commander (p.38)
What are the 3 type of fluid (and their mixture with water) accepted by Wizz Air ?
TYPE I, TYPE II, TYPE IV (p.38)
Describe the One Step De-icing/Anti-icing procedure?
single application of heated and diluted de-icing/anti-icing fluid (p.39)
How long is the Hold Over Time of the One Step de-icing/anti-icing procedure (short or long?
short hold over time (p.39)
In the One Step de-icing/anti-icing procedure when does the Hold Over Time starts?
at the beginning of the application of the fluid (p.39)
Describe the Two Steps De-icing/Anti-icing procedure ?
first apply heated de-icing fluid and then apply a protective anti-icing fluid consecutively (p.39)
In the Two Steps De-icing/Anti-icing procedure when does the Hold Over Time starts ?
from the beginning of the application of the second fluid (p.39)
As no de-icing/anti-icing liquid can be sprayed over the engines how is ice or snow removed ?
- deposits of snow should be mechanically removed (broom or brush)
- Any frozen deposits on the lower surface of the engine or engine blades may be removed by hot air (p.40)
What is a Local De-icing?
when only a few scattered areas of a surface or the plane require de-icing and when no hold over time is likely to be required just a quick clean up (p.41)
What are the conditions that could lead to perform a Local de-icing?
- when HOT is not required
- Fluid type/concentration as per One Step DAI
- Symmetrical application (ex.can’t be only one wing it has to be both) (p.41)
Is HOT applicable for Local De-icing?
NO(p.41)
What is the most economical, faster and environmentally friendly De-icing procedure?
by the use of assisted forced air requiring only 50% of de-icing fluid(p.41)
Should you use HOT table for a Forced Air Fluid De-icing with Type I fluid?
Not Allowed unless combined with a Two steps Anti-icing where ONLY Generic HOT table can then be used (p.41)
Why is Forced Air never used for Anti-icing ?
because it may degrade the Type II and IV fluid performance (p.42)
What type of fluid/s should be used for maximum protection?
undiluted, unseated TYPE II or IV (p.42)(4.3.9.6)
If HOT has expired and a new anti-icing treatment is necessary can anti-icing liquid be sprayed again directly?
NO, firstly a de-icing must be performed before anti-icing liquid can be sprayed (p.43)
Can the APU be running during an de-icing/anti-icing treatment?
YES, but all bleed air valve must be closed (p.44)(4.3.10.2.3)
Can the aircraft be dispatched without the confirmation of a Post Treatment Check?
NO (p.45)
Is the TIME reported for a de-icing/anti-icing treatment in UTC or Local Time?
Local Time (p.45)
Regarding Type I fluid, if you increase the concentration of this fluid in the fluid/water mix, does this increase the hold over time of the fluid ?
NO (p.48)(4.4.1.1)
Describe Anti-icing process. From spraying to full dilution of the fluid.
- anti-icing fluid, which freezes at very low temperature (-30ºC) is applied of a clean surface (post de-icing)
- The fluid absorbs the frozen precipitation which melts but does not freeze
- As the fluid becomes more and more diluted its freezing temperature increases
- When the fluid temperature reaches OAT or the aircraft skin temp, anti-icing fluid fails and the frozen precipitation accumulated (p.51)
Define Dry Runway?
A runway which is neither wet or contaminated (p.53)
Define Damp Runway?
A runway which is not dry but without shiny appearance (p.53)
Define Wet Runway?
runway covered with water, less the 3mm (>3mm contaminated runway), shiny appearance but without standing water (p.53)