Takeoff in ice pellets/heavy snow/with no HOT

[jondc9]

HI
I am in the USA and there seems to be a great controversy here. The Subject:
Taking off (departing) in heavy ice pellets or any precip that does not have what we call a HOLD OVER TIME established.

The idea is that taking off in heavy ice pellets, even though they might not be sticking to the wings will lead you into an area of precip that might exceed FAR121 requirements for anti ice equipment.

I am talking about large airliners here equipped with anti-ice equipment.

This is a relatiely NEW thing from our FAA. What do you guys and gals know about this? I know one major airline is following this new regulation and one is not...yet the FAA's programs are individually administered by each airline's inspector (POI).
regards
jon
[email protected]

[sidestickhumper]

Hold over time has nothing to do with inflight procedures, due to the fact, that the fluid will be removed on the moment of rotation (at least most of it)

To my knowledge it's less a problem in flight but the degradation of the deice/ anti ice fluids on the ground. The ice pellets can adhese to the Type I, II, III and IV fluids and mix with them or can degrade the thickener molecules on impact. Therefore there are no HOT established for that kind of precip.


To answer your question, we are following these regulations...

Please correct me if I'm wrong

Side

[Ice-bore]

There would appear to be two issues here. Firstly, are the designated aircraft surfaces free of frost, ice, slush and snow immediately prior to takeoff and secondly, has the aircraft been certified for takeoff/flight when snow pellets, ice pellets, heavy snow, moderate and heavy freezing rain and hail is falling (i.e. conditions not covered by the current HOT’s)?
A lot of work has been carried out to substantiate the currently published times, however, the less common 'events' detailed above have not been included in the programme to date. If you look at the holdover time tables for all current fluid types you will see that the more severe conditions are grouped under the heading 'Other' and there is a Caution stating, "No holdover time guidelines exist."
In my opinion this does not necessarily preclude takeoff under such conditions. The requirements are that i). a 'Pre-takeoff Contamination Check' is carried out to confirm that surfaces are clear and ii). the aircraft is certified for takeoff/flight under the prevailing conditions.
Obviously if the conditions are that severe, ice and/or snow will be detected during the 'Pre-takeoff Contamination Check' and either the departure delayed or further de-/anti-icing, plus additional 'Pre-takeoff Contamination Check', carried out, until the surfaces are found to be clear.
With regard to the certification issue, certain aircraft types may not be certified for flight in snow pellets, ice pellets, heavy snow, moderate and heavy freezing rain or hail. However, it is assumed that if the aircraft is certified, the anti-icing systems will be fully effective.
It is noted that the FAA have included a note in FSAT 05-02 (10/18/05) stating, "The FAA does not approve takeoff in conditions of moderate or heavy freezing rain", however, they do not appear to restrict takeoff during snow pellets, ice pellets, heavy snow or hail……

[jondc9]

from the FAA:

<Therefore, even though ground operations in ice pellets that are not adhering to the aircraft may not create an immediate hazard, takeoff in such conditions may expose the aircraft to inflight icing that may exceed the ability of the ice protection systems of the aircraft to remove the ice. PIs are reminded that the operator must determine if the icing conditions expected aloft might adversely affect the safety of the flight.>


this is a more difficult situation than one might imagine. more complex issues. I understand all that the fine posters have written, but still, there is one airline taking off in heavy snow or ice pellets and another is not. the faa is still short of answers.

regards

jon


hope you all google the FAA, ice pellets etc to get more info and FLY SAFE.

[Torque2]

To the best of my knowledge Airbus does not allow take off in conditions of Ice Pellets etc according to their FCOMS for the 319/20/21.

[junior_man]

Ice pellets penetrate the de ice fluid and no holdover time is stated for them, therefore takoff should be prohibited.

Certain airlines are claiming that it should be Captain's descretion to take off anyways and are effectively ignoring the rule. Perhaps the FAA will actually do something about it before these guys have another accident.

Takeoff into ice pellets also exposes you to a high risk of encountering freezing rain at a slightly higher altitude. Not a good thing.

[Safety Guy]

I believe that the FAA's reasoning for their recent circular on this subject was that there has been no holdover time testing done on those contaminants, and therefore, there is no way to discern if one is operating with a clean aircraft.

[FIRESYSOK]

If there is no holdover time established, then maybe you shouldn't go flying. I understand that precip type, intensity etc., is variable, and subject to a range of interpretation, however, I may hesitate to take off lacking positive guidance from the holdover table. PIC judgement is a big piece of the equation, however.

Come to think of it, I don't believe I'd recognize a snow or ice pellet. Anyone in colder climates have experience with this type of precip? I think that lack of experience and perspective in the "lower-48" may be driving the new AC's.

My employer is working on updating company policy regarding operations in ice pellets, presumably in responce to the AC.

[KLMer]

Well all i know is that with my company if there is not HOLD OVER time given for a particular wx condition then its very simple..... go get another cup of tea, as were not going anywhere!!