Runway overruns
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Runway overruns
I hope it is ok to start a separate thread on this, following on from the AF incident at YYZ last week (Mods, please merge if this is not appropriate).
Whenever safety improvements at airports are discussed, I would usually be the first one to stand up and say "how about making the roads safer, the biggest risk is always in getting to and from the airport".
However, incidents such as last week's over-run are often opportunities to improve safety, especially if there are methods which have been implemented elsewhere (eg at JFK), and which appear be effective.
As anyone in the Midlands knows, there is a vociferous anti lobby here at CVT, and one of their oft-reported gripes is their claim that the runway "is not long enough".
Whilst the chances of a serious incident are always small, "on a long enough timeline" (to quote TD in Fight Club), lots of very small numbers add up to one.
05 at CVT is just "yards" from one such dangerous road junction, and there is an embankment leading on to it which wouldn't do any a/c's hull much good in the best conditions.
BHX is also very close to the A45, although talk of runway extensions might well mean bridging this over, and presumably leading to an over-run into surrounding fields, whereas LTN also often gets mentioned for having a steep embankment with approach road at the bottom.
I'd hate to think of the consequences of an over-run onto the mainline at LGW either.
My understanding is that at CVT at least, the "start up strips" are of the same surface material as the rest of the runway, and therefore can they really offer much help in slowing down an aircraft in an emergency?
Please excuse my lack of detailed knowledge about runway surface materials, but I would appreciate it if anyone could shed some light on the potential costs and benefits of these features.
Whenever safety improvements at airports are discussed, I would usually be the first one to stand up and say "how about making the roads safer, the biggest risk is always in getting to and from the airport".
However, incidents such as last week's over-run are often opportunities to improve safety, especially if there are methods which have been implemented elsewhere (eg at JFK), and which appear be effective.
As anyone in the Midlands knows, there is a vociferous anti lobby here at CVT, and one of their oft-reported gripes is their claim that the runway "is not long enough".
Whilst the chances of a serious incident are always small, "on a long enough timeline" (to quote TD in Fight Club), lots of very small numbers add up to one.
05 at CVT is just "yards" from one such dangerous road junction, and there is an embankment leading on to it which wouldn't do any a/c's hull much good in the best conditions.
BHX is also very close to the A45, although talk of runway extensions might well mean bridging this over, and presumably leading to an over-run into surrounding fields, whereas LTN also often gets mentioned for having a steep embankment with approach road at the bottom.
I'd hate to think of the consequences of an over-run onto the mainline at LGW either.
My understanding is that at CVT at least, the "start up strips" are of the same surface material as the rest of the runway, and therefore can they really offer much help in slowing down an aircraft in an emergency?
Please excuse my lack of detailed knowledge about runway surface materials, but I would appreciate it if anyone could shed some light on the potential costs and benefits of these features.
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jabird
as you imply there are several factors to whether an aircraft will overrun -
AF358 may have suffered from any or all of
What happens after an aircraft overruns should be irrelevant as this is already an unacceptable occurrence, IMHO.
To allow for overruns may allow more risk taking. Jeremy Clarkson (in jest) suggested doing away with seatbelts and putting a metal spike in the middle of the steering wheel, theorising it would deter accidents rather than prevent them.
If GTAA want to prevent another overrun, a reinforced concrete wall just beyond the end of 24L might be the Clarkson way of preventing a future incident by forcing pilots to consider more strongly the consequences of press-on-itis.
as you imply there are several factors to whether an aircraft will overrun -
AF358 may have suffered from any or all of
What happens after an aircraft overruns should be irrelevant as this is already an unacceptable occurrence, IMHO.
To allow for overruns may allow more risk taking. Jeremy Clarkson (in jest) suggested doing away with seatbelts and putting a metal spike in the middle of the steering wheel, theorising it would deter accidents rather than prevent them.
If GTAA want to prevent another overrun, a reinforced concrete wall just beyond the end of 24L might be the Clarkson way of preventing a future incident by forcing pilots to consider more strongly the consequences of press-on-itis.
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Everyone's banging on about the fact that 24L at Toronto isn't grooved. Dunno about this surface in detail, but there's a perfectly acceptable asphalt non-grooved surface known as Porous Friction Course (PFC) Heathrow used to have this and very effective it was, too. It has a couple of downsides; the pores get filled up with rubber and if you allow moisture in it to freeze, it blows the surface off. It'd be interesting to actually hear from someone who knows what the surface really is, what it's current friction value is and what their maintenance philosophy is. Grooves in harsh winter conditions might not be the best policy.
We have a fantastic grooved surface at Gatwick, but it's hard work cleaning the rubber out of the grooves all the time.
Now, Coventry. There's no way that runway isn't long enough. If it wasn't, then there'd be over-runs there every day - I haven't heard of any. If locals are saying that they want it longer, then I can only conclude that they want bigger, heavier types operating from a lengthened strip. Great!! Good to see they're getting behind the operation at last!
If someone touches down in the stop end of a runway, (not implying AF did) then it doesn't matter if it's 15Km long, they'll still run off the end.
Cheers,
The Odd One
We have a fantastic grooved surface at Gatwick, but it's hard work cleaning the rubber out of the grooves all the time.
Now, Coventry. There's no way that runway isn't long enough. If it wasn't, then there'd be over-runs there every day - I haven't heard of any. If locals are saying that they want it longer, then I can only conclude that they want bigger, heavier types operating from a lengthened strip. Great!! Good to see they're getting behind the operation at last!
If someone touches down in the stop end of a runway, (not implying AF did) then it doesn't matter if it's 15Km long, they'll still run off the end.
Cheers,
The Odd One
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Mark D,
I agree that any overrun is unacceptable, but they can and do still happen. Would Mr Clarkson be arguing that aircraft passengers shouldn't wear seatbelts either? And how often do those lifejackets we get briefed on ever get put to use (recent Bari incident possibly being a rare exception)?
Perhaps if airlines really wanted to do a "public safety" briefing, they should have an END of flight announcement saying:
1) Familiarise yourself with that hire car and local driving conditions, before taking it out onto the open road.
2) Don't forget your sunblock (or in the case of Ryanair, can we sell you some sunblock for £10 per tube + £2 supplement per factor increment).
3) If you are going to play away from home, make sure you use a condom.
There is talk of travel agents becoming sued for not providing this advice, and with the rise of direct booking, could airlines be expected to have the same responsibility?
The Odd One, has any aircraft ever overshot the runway at the railway end (sorry I don't have the heading numbers to hand) of LGW?
CVT is "short" in comparison to most other UK airports operating 737s, but this does not make it "not long enough" - one the nimbys did actually try to quote PPRUNE in his presentation, together with Boeing data for a 737-500s runway requirements (when fully laden and flying at maximum range, rather than just hopping down to Malaga).
So we don't live in a risk free or accident free world, and as runway over-runs will happen, if there is technology which will help reduce the damage such incidents cause, at a cost which is in proportion to the benefits, should we be seeing more of it?
I agree that any overrun is unacceptable, but they can and do still happen. Would Mr Clarkson be arguing that aircraft passengers shouldn't wear seatbelts either? And how often do those lifejackets we get briefed on ever get put to use (recent Bari incident possibly being a rare exception)?
Perhaps if airlines really wanted to do a "public safety" briefing, they should have an END of flight announcement saying:
1) Familiarise yourself with that hire car and local driving conditions, before taking it out onto the open road.
2) Don't forget your sunblock (or in the case of Ryanair, can we sell you some sunblock for £10 per tube + £2 supplement per factor increment).
3) If you are going to play away from home, make sure you use a condom.
There is talk of travel agents becoming sued for not providing this advice, and with the rise of direct booking, could airlines be expected to have the same responsibility?
The Odd One, has any aircraft ever overshot the runway at the railway end (sorry I don't have the heading numbers to hand) of LGW?
CVT is "short" in comparison to most other UK airports operating 737s, but this does not make it "not long enough" - one the nimbys did actually try to quote PPRUNE in his presentation, together with Boeing data for a 737-500s runway requirements (when fully laden and flying at maximum range, rather than just hopping down to Malaga).
So we don't live in a risk free or accident free world, and as runway over-runs will happen, if there is technology which will help reduce the damage such incidents cause, at a cost which is in proportion to the benefits, should we be seeing more of it?
Last edited by jabird; 8th Aug 2005 at 23:35.
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The Odd One, has any aircraft ever overshot the runway at the railway end (sorry I don't have the heading numbers to hand) of LGW?
The main runway is 08R in that direction, and I've no records of an over-run in EITHER direction, certainly not in the last 16 years. That's over 7.5 million movements on the runway without an over-run, which comes out as 'remote' as a risk factor. Of course, we like to work to 'extremely remote' ie 1 x 10 to the -9, so we look at other similarly-sized runways with similar levels of traffic, construction, weather etc and you can get down to this level of risk quite easily.
Actually, there's quite a lot before you get to the railway. The 'official' stop end of 08R is a little way before the end of the paved surface, then there's some flat grass before the first upstanding obstruction, which is the Localizer. Then there's an airside road, then the pushbike shelter and landside fence, which is probably the first non-frangible obstruction. Then there's a landside perimeter road, another fence, then the A23, a dual carriageway before you actually get to the railway line.
Sounds like your NIMBY has shot themselves in the foot.
Good luck with the Thompson programme this Summer; hope it attracts some more players.
Cheers,
The Odd One
