Rutting ?

[lion-g]

Hi Guys,

I was wondering how Wet snow with rutting as reported by the tower is going to affect our performance, be it T/O or LDG.

It was reported recently by LHR tower.

In my opinion, wet snow with rutting has a poorer braking action as compared to uniform wet snow contamination.

Any comments ?
Thanks for your input.

[zerozero]

I'm not sure I agree with your experience about uniform wet snow having better braking than "rutted" snow.

If you can position your mains in the ruts, in theory you have less snow between the rubber and the asphalt, perhaps even just water.

But I have never seen any tower differentiate between uniform and rutted snow.

I think for performance calculations it's best to just consider an average depth of wet snow and go from there. No doubt there will be a decrement. This is where experience and good judgment come into play.

[Checkboard]

Ask them if the reported depth is an average, the maximum (i.e. the 'ridges') or the minimum (i.e. the 'ruts'). :cool:

[Sir George Cayley]

Zero Zero, you Alaskans have bigger better ruts than we do in lil ol Engerland.

The snow last Saturday whilst heavy was only around freezing and the ground wasn't cold soaked. Daytime temps were soon above freezing.

It's up to each team on the runway to call it as they see and at least Heathrow have had 2 winters experience.

Nevertheless, I wouldn't apply your assessment to here.

Also, having spent millions on new kit I'd want my money back if it left ruts.:{

[Stuart Sutcliffe]

Rutting
Lions can do it ...

But The Rutles do it better ...... :ok:

Monty Python, Rutles, Rutland Weekend Television (http://www.neilinnes.org/rutles.htm)

[lion-g]

Thanks for your replies.

I was just pondering what effect does rutting have on performance, apart from rolling on an uneven takeoff surface.

Anyway, just for info, last Sat report was "Contamination on RW09R as follows :- "15mm wet snow with rutting, 20 mm wet snow with rutting 30mm wet snow with no rutting"

Any comments ?

Cheers

[zerozero]

I'm just being honest.

I find the added description of "rutting" to be interesting but not worth more than a pause in my performance considerations.

Personally, I would take the greatest snow depth (30mm in this case) and base ALL my performance on that measurement. Everything else is "nice to know", but the maximum depth of the wet snow is a "need to know".

:)

[Vizsla]

The Stags get very aggressive

[overun]

Does the met office know of this ?

l wouldn`t bother trying to tell them. Flyte Sim ?