1/3rd of LHR flights cancelled today
By 1800 Saturday, just as the snow (in all a few centimetres) STARTED, Heathrow went down to single runway ops, the south runway being closed. How can this be ? The majority of airports around the world are single (significant) runway, and in snow areas they just manage to carry on operating through all winter weather. Not close a main runway at the first snowflake !
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WHBM - This is a pure guess, but single runway operations would be required whilst the other runway was being swept. Sweeping can start with very little snow visible on the runway. For any single runway airport the only option is to close for runway sweeping, the only question is for how long.
Presumably the Putney Girlie was quite pleased about Heathrow being restricted, so she and the rest of her millionaire neighbours who live on West Hill in Wandsworth-Putney could enjoy their Sunday morning cocktail parties without any distant sound from those nasty aeroplanes approaching Heathrow containing the electorate.
WHBM - This is a pure guess, but single runway operations would be required whilst the other runway was being swept. Sweeping can start with very little snow visible on the runway. For any single runway airport the only option is to close for runway sweeping, the only question is for how long.
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The problem with a dual runway airport is the timing of closing a runway for snow clearing.
If you leave it until the same point at which you'd be clearing a single runway airport, it's too late as the other runway will be too contaminated by the time you get to it.
You need to close the first runway earlier than you think to enable it to be cleared and ready to operate, which in turn enables you to close the other runway before the point at which it becomes unsafe and would close anyway.
With all the time buffers you need to build in, the point at which you start thinking that you should be closing the first runway, it's already too late!
.....and of course, at an airport which is scheduled to 99% capacity, you need to set the flow rate to anticipate the first closure by an hour or so to enable the flow to kick in.
It seems more like an art than a science.
WHBM, re Russia, it's different snow. Seriously. Dry, compacted snow is nothing like the usual UK slushy snow. From my understanding, flight crews are far happier to operate from runways contaminated by dry, compacted snow than slush.
If you leave it until the same point at which you'd be clearing a single runway airport, it's too late as the other runway will be too contaminated by the time you get to it.
You need to close the first runway earlier than you think to enable it to be cleared and ready to operate, which in turn enables you to close the other runway before the point at which it becomes unsafe and would close anyway.
With all the time buffers you need to build in, the point at which you start thinking that you should be closing the first runway, it's already too late!
.....and of course, at an airport which is scheduled to 99% capacity, you need to set the flow rate to anticipate the first closure by an hour or so to enable the flow to kick in.
It seems more like an art than a science.
WHBM, re Russia, it's different snow. Seriously. Dry, compacted snow is nothing like the usual UK slushy snow. From my understanding, flight crews are far happier to operate from runways contaminated by dry, compacted snow than slush.
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It's a good question as to how airports can actually clear snow without any disruption to air transport movements where snow clearing is required. If an airport has the capability to plough / sweep and or blow snow in one pass of the runway, some critical factors in avoiding disruption would be aircraft spacing, rate of snow fall and sweeping speed.
As far as I am aware, some Scandinavian airports claim to never close, not never to suffer from disruption. I don't think anyone involved in snow clearing would take that kind of liberty with nature. Claiming to never close is already pushing your luck.
Many of our practices are down to culture. I can remember landing in a passenger jet with no fire cover present up in the arctic. This appeared to be culturally acceptable, given no medical facilities in the area either, but not elsewhere.
As far as I am aware, some Scandinavian airports claim to never close, not never to suffer from disruption. I don't think anyone involved in snow clearing would take that kind of liberty with nature. Claiming to never close is already pushing your luck.
Many of our practices are down to culture. I can remember landing in a passenger jet with no fire cover present up in the arctic. This appeared to be culturally acceptable, given no medical facilities in the area either, but not elsewhere.
Gonzo, these are some good points, but the thing about snow elsewhere being dry/powdery stuff is not altogether correct. Certainly it might be true today, when the temperatures in St Petersburg are around -20C with low humidity, but in the winter shoulders, in November and March, you get the same around-zero temperatures and snow conditions as here today.
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Surely the obvious comparison to assess Heathrow's performance is against Gatwick, Stansted and Luton through the same period. Anyone out there got the data ? Or indeed correct me if I am wrong for supposing those are valid comparators ?
Paxing All Over The World
This is taken from an article in The Independent Thousands grounded as 'snow plan' at Heathrow fails again - Home News - UK - The Independent
After the December 2010 debacle, which cost airlines more than £50m and wrecked the travel plans of around one million people, the airport has invested heavily in new equipment. BAA has worked with airlines and air-traffic control authorities to formulate a new snow plan. In a statement yesterday, the airport said: "Our snow plan has worked far better than in previous years."
Did a winter in Helsinki and they may hardly ever smile but they sure know how to shift snow. Think they used 15-20 miles slot in traffic to do a runway. I was very impressive watching 5 of everything going for it.
And gonzo is correct landing on a white strip in -20 with the approprate performance penalties is quite a suprising experence (certainly not a bad one). In fact our home based runway only got cleared when the glass ice built up to such an extent that the cutter thing that chops grooves into ICE couldn't deal with it. Only bum twitcher was getting to your car.
