Deicing

helico55helico55
in Operational questions

Hi.
Question about deicing. How many time I have before takeoff after deicing ?
Because I saw mayday canal D we have 20 minutes before takeoff.
Is it same thing with majestic ?

Comments

  • jpgmultimodaljpgmultimodal

    Depends of the fluid. see there:
    https://aircrafticing.grc.nasa.gov/2_3_3_1.html

  • helico55helico55
    Ok thank but majestic is there time before takeoff ?
    From what temperature I must request deicing fms ?
    For sure only if there is precipitation.
  • FraPreFraPre

    I assume that Majestics does not implement every fluid type, so there are no different holdover times. So, if you should find new use on the control surfaces on the way to the runway, which cannot be removed by deicing, you would have to request deicing on the ground again. Often there are defined deicing areas on the ground near the runways, so that the way to the start is no longer that far. But I think it isn't all that deeply simulated. On the contrary, during the flight I have the feeling that the ICING CONDITIONS message has been implemented a little too generously and that it is too often unnecessary and incomprehensible.

    The best way to orientate yourself is to use the official AOM definitions. According to these, ICING CONDITIONS exist if:
    • The Static Air Temperature (SAT) on the ground and for take-off is 10 ° C (50 ° F) or below, or
    • the SAT in flight is 5 ° C (41 ° F) or below, and
    • Visible moisture in any form is present (such as clouds, fog with visibility of one statute mile or less, rain,
    snow, sleet or ice crystals).
    • Ice accretion on aerodynamic surfaces is not considered to exist at temperatures of -40 ° C or below.
    Icing conditions also exist when:
    • The SAT on the ground and for take-off is 10 ° C or below when operating on ramps, taxiways or runways
    where surface snow, ice, standing water or slush may be ingested by the engines or freeze on engines,
    nacelles or engine sensor probes.
    As with any meteorological hazard, the most effective procedure is to stay away from the known areas
    involved.

  • kroswyndkroswynd

    I don't recall our finite details but it was more or so modelled from what we do in the US where we use primarily Type 1 and Type IV fluids, and the different mixture concentrations. When I have some time will have to go back and check on how we set it up.

    We did not simulate it to be as precise or restrictive as it is in the real world, but we did implement the fact that if conditions on the ground exhibited ice accretion due to freezing rain or snow (I don't think the wx add-ons allow for sleet) driven by the weather add-ons, the pushback sequence whether by our FMS or GSX would invoke the deicing procedure for type I or IV and the concentration/mixture required.

    @FraPre - has broken it down quite well in the previous post as to when the deicing requests would be invoked.

Sign In or Register to comment.