De-icing LHR

[too_sleepy]

Hi
Hope I've got the right forum. We were in LHR on Saturday night, one of the lucky to get out. ATC were great as usual and asked all callers for a holdover time. Assume this was to coordinate traffic so no one got stuck on the taxiway needing another de-ice.
Well, one crew called for clearance, and responded to the holdover question with "we have no holdover time, we don't need de-icing".
I'm new to flying but I couldn't figure how anyone would think they didn't need de-icing. It was -1 and light snow. This was about 20:00 and weather was getting worse.
I kept thinking it weird that there's nothing anyone else could do to stop them, they got a clearance and assume left shortly after we did.

Am I missing something? Or was it just plain ignorance and stupidity?

Thanks

[sleeper]

Do you know what type of aircraft and airline it was?

All the type's I flew are not allowed to depart with any contamination on the upper wing surface.

[gonnabe]

There will always be hot shots that have made up their own theories about how much ice/snow their plane can take. Usually from less serious airlines.

[Mad (Flt) Scientist]

@too_sleepy

Since this occurred at LHR can I suggest you file a CHIRP (http://www.chirp.co.uk/index.asp) report? It won't be used for disciplinary purposes, but it may stop it happening again; the fact that this crew got away with it once is no guarantee they'll do so again, never mind the fact that what they did is almost certainly a violation of the relevant operational regs.

@sleeper

Its not even in the OEM's control - the rules pertaining to the clean aircraft concept are in the operational regs. There are a couple of grandfathered cases that violate the regs (a very murky area, legally, IMHO) but the regs themselves are pretty clear... 121.629 is the US airline version of the rule, but the wording is pretty similar everywhere. So pretty much everyone is (or should be) in the same boat.

[Sir George Cayley]

Is the devil in the detail?

If you have been anti iced having arrived clean, could you say "..don't need de icing'?

SGC

[Denti]

@sleeper, there is always the odd exception. The 737NG is approved to take off with some limited contamination on the upper wing surface. However not the kind you get from any kind of snowfall which is usually spread more or less evenly over the whole wing. It is just a provision to allow some frost accretion with a cold soaked wing in humid weather.

@SGC, in that case you still have a hold-over time which is pretty limited with the high temperature and continuous snowfall.

[crwjerk]

Not sure whether it's one or two step over there, but the holdover time would still be applicable as it's the Anti -icing step that starts the clock ticking, right? If he's anti-iced after arriving clean, he would certainly have a holdover time, clean wing or not.
Seems to me it was just a case of " we'll be right jack".........