Rutting ?
Thread Starter
Joined: Dec 2007
Posts: 127
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From: Changi
Rutting ?
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.
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.
Joined: Jun 2001
Posts: 518
Likes: 0
From: Chicago, IL, USA
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.
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.
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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.
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.
Joined: Mar 2010
Aviation Qualifications: ATP+Mil
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From: Hamburg
Rutting
Lions can do it ...
Lions can do it ...
Monty Python, Rutles, Rutland Weekend Television
Thread Starter
Joined: Dec 2007
Posts: 127
Likes: 0
From: Changi
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
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
Joined: Jun 2001
Posts: 518
Likes: 0
From: Chicago, IL, USA
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".
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".
