Air France crash at YYZ (Merged)
TSB Press Conference Details
Listened in by phone -- caveat poor sound quality
- Doors 3L - 4L not opened because fire immediately outside.
- 2L came open by itself while a/c bouncing down slope.
- 3R had no slide, CC closed it because sharp objects in vicinity.
- Rwy will be returned to service after studies on skid marks completed.
- Extinguisher and oxy bottles need to be removed before safe to remove wreckage with backhoes etc.
- FDR shows touchdown at Vref 143 kt. in quartering tailwind 4000' approx down runway. 5000' remaining sufficient for dry, but not wet.
- Exited rwy at 79 kt.
- Question asked about poor deceleration [64 kt. over 5000' ] -- TSB will investigate.
- PIC interviewed Saturday; confidentiality requirements prevent disclosure.
Last edited by RatherBeFlying; 7th Aug 2005 at 19:52.
Tsamaya sentle
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The number of poor laymen´s comments and unprofessional and/or unfounded, merely speculative posts in this thread seems to have reached a new all-time high at PPRuNe. The constant quoting of equally ill-informed media sources does not help either...
I have rarely read so much obvious rubbish, except in the Jetblast section of the bulletin board. Gone are the days where professionals discussed rumours and news, and all others just took notice, and learned.
I have rarely read so much obvious rubbish, except in the Jetblast section of the bulletin board. Gone are the days where professionals discussed rumours and news, and all others just took notice, and learned.
From RBF:
FDR shows touchdown at Vref 143 kt. in quartering tailwind 4000' approx down runway. 5000' remaining sufficient for dry, but not wet.
Exited rwy at 79 kt.
"Question asked about poor deceleration [64 kt. over 5000' ] -- TSB will investigate."
Good question, wonder how you would make out rejecting close to V1 at max weight for the conditions if that is all the deceleration available?
Sounds like the investigators still have a lot of work to do.
FDR shows touchdown at Vref 143 kt. in quartering tailwind 4000' approx down runway. 5000' remaining sufficient for dry, but not wet.
Exited rwy at 79 kt.
"Question asked about poor deceleration [64 kt. over 5000' ] -- TSB will investigate."
Good question, wonder how you would make out rejecting close to V1 at max weight for the conditions if that is all the deceleration available?
Sounds like the investigators still have a lot of work to do.
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"TORONTO, Aug 7 (AFP) - The Air France Airbus jet which crash landed at Toronto's airport touched down too far along the rain-soaked runway to stop in time before overshooting and bursting into flames in a ravine, a senior investigator said Sunday.
"I am pretty convinced that there was no way that the aircraft was going to be able to stop before the end with the runway condition that we had, the water on the runway, and the braking action which was poor," Canadian Transportation Safety Board lead investigator Real Levasseur told reporters Sunday.
"My preliminary estimate is that there was no way this airplane could have stopped before the end" of the runway, he stressed.
Levasseur is leading the probe into Tuesday's crash landing of the Air France jet during a violent thunder storm.
All 12 crew and the flight's 297 passengers survived the near disaster.
The plane touched down about 4,000 feet (1,219 meters) along the runway -- close to midway -- leaving the co-pilot, who was in control of the jet, only 5,000 feet (1,524 meters) to bring the jet to a halt, Levasseur said.
Under normal conditions, this type of aircraft could have stopped in time, he said.
It was traveling "fairly close" to the correct landing speed -- at 148 knots instead of the typical 140 knots -- pushed along by a slight tailwind, he said.
But, because the runway was slick due to rain, the brakes were less effective and it took longer to decelerate, Levasseur said. Investigators will conduct simulations to confirm this, he added.
By the time it reached the end of the runway, the plane had only slowed to 79 knots before skidding off into a ravine.
Levasseur said investigators must now determine why the aircraft overshot the runway during landing."
Seems my poor laymen´s comments and unprofessional and/or unfounded, merely speculative post 5 days ago wasn't that far from the truth...
"I am pretty convinced that there was no way that the aircraft was going to be able to stop before the end with the runway condition that we had, the water on the runway, and the braking action which was poor," Canadian Transportation Safety Board lead investigator Real Levasseur told reporters Sunday.
"My preliminary estimate is that there was no way this airplane could have stopped before the end" of the runway, he stressed.
Levasseur is leading the probe into Tuesday's crash landing of the Air France jet during a violent thunder storm.
All 12 crew and the flight's 297 passengers survived the near disaster.
The plane touched down about 4,000 feet (1,219 meters) along the runway -- close to midway -- leaving the co-pilot, who was in control of the jet, only 5,000 feet (1,524 meters) to bring the jet to a halt, Levasseur said.
Under normal conditions, this type of aircraft could have stopped in time, he said.
It was traveling "fairly close" to the correct landing speed -- at 148 knots instead of the typical 140 knots -- pushed along by a slight tailwind, he said.
But, because the runway was slick due to rain, the brakes were less effective and it took longer to decelerate, Levasseur said. Investigators will conduct simulations to confirm this, he added.
By the time it reached the end of the runway, the plane had only slowed to 79 knots before skidding off into a ravine.
Levasseur said investigators must now determine why the aircraft overshot the runway during landing."
Seems my poor laymen´s comments and unprofessional and/or unfounded, merely speculative post 5 days ago wasn't that far from the truth...
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Just out of interest, what are the usual mainwheel tyre pressures on the A346? I only ask this because I recall from groundschool many years ago a way to work out an aquaplaning speed from tyre pressure - I think it's 8.7xsqrt P where P is the tyre pressure. I'm not sure of the input or output units for this formula, though. It may be of some interest, it may not.
Just a thought.
16B
Just a thought.
16B
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Thanks, Sky. So...gives an aquaplane speed of 123-129kts. (presuming the formula's output is in knots)
A possibility, then? Again, just an (unqualified) thought (I'm a C-130 driver).
Just wondering HOW short the (alleged) remaining 5000ft would've been on LDR for the conditions. Obviously AUM would have to be 'estimated'.
16B
A possibility, then? Again, just an (unqualified) thought (I'm a C-130 driver).
Just wondering HOW short the (alleged) remaining 5000ft would've been on LDR for the conditions. Obviously AUM would have to be 'estimated'.
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Judging from today's press briefing by the TSB, as reported on this thread by Rather B Flying and Capt. KAOS, we are now reasonably sure what happened but exactly why it did is still to be determined.
We Canadians should not lose sight of one highly significant happening in this whole chain of events. Mirabile dictu, for once, a Canadian government minister, a Liberal at that (Jean Lapierre, the transport minister) actually spoke the truth in public (when he announced, just hours after the accident, that he had been given to understand that the pilot landed long) [see my post of 3 Aug on p. 12 of this thread].
Rockhound
We Canadians should not lose sight of one highly significant happening in this whole chain of events. Mirabile dictu, for once, a Canadian government minister, a Liberal at that (Jean Lapierre, the transport minister) actually spoke the truth in public (when he announced, just hours after the accident, that he had been given to understand that the pilot landed long) [see my post of 3 Aug on p. 12 of this thread].
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Regarding the earlier comments about the one (or two??) members of the public who claim to have entered the fuselage of the plane after it crashed, it seems that they claim to have come from the highway, and not from inside the airfield perimeter.
Having heard one of them interviewed on CBC Newsworld, I personally have suspicions about the validity of their claims.
Having heard one of them interviewed on CBC Newsworld, I personally have suspicions about the validity of their claims.
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"Possible plans to extens over-run area"
Interesting point raised a couple of pages back, about possible plans to increase the over-run area at the end of the runway and fill the ravine.
Now I know it's not a great way of stopping an aircraft, but the ravine did stop the Airbus from carrying straight on across a crowded highway.
If the runway over-run area had been extended across the ravine, wouldn't it have been very likely that the aircraft would have gone straight onto the highway, impacting several cars filled with that old-fashioned, dangerous, avaiation fuel called PETROL, resulting in an almost instant inferno in which possibly all pax and crew, as well as a number of car drivers, would have been incinerated?
Just maybe the ravine did everyone (apart from the Airbus hull) a favour???
Is a runway extension designed for over-run constructed specially in some way to add retarding factors into its surface? (like the gravel "escapes" used to help runaway trucks on steep highway hills?)
(I'll just add my "well done" to the crew for the life-saving evac. You're trained for it, but everyone hopes you'll only ever have to serve coffee and tea. Would have lost a lot of souls if the evac had been slower)
Now I know it's not a great way of stopping an aircraft, but the ravine did stop the Airbus from carrying straight on across a crowded highway.
If the runway over-run area had been extended across the ravine, wouldn't it have been very likely that the aircraft would have gone straight onto the highway, impacting several cars filled with that old-fashioned, dangerous, avaiation fuel called PETROL, resulting in an almost instant inferno in which possibly all pax and crew, as well as a number of car drivers, would have been incinerated?
Just maybe the ravine did everyone (apart from the Airbus hull) a favour???
Is a runway extension designed for over-run constructed specially in some way to add retarding factors into its surface? (like the gravel "escapes" used to help runaway trucks on steep highway hills?)
(I'll just add my "well done" to the crew for the life-saving evac. You're trained for it, but everyone hopes you'll only ever have to serve coffee and tea. Would have lost a lot of souls if the evac had been slower)
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With regards aquaplaning speeds, bear in mind these numbers are not to be used in a scientific manner. Merely guidance.
But also to note, these 8.7 times figures (i.e. 9 times as the rough guide) are for a wheel that is already rotating. These speeds can be reduced to, in some cases, around 7.5 times for a stationary wheel. Hence the recommended Boeing technique on a wet/contaminated runway is for a firm touchdown to help increase the friction required to spin the wheel up (also the excuse I use on dry runways for my landings. "Sorry girls, Boeing recommended landing"..... :-) ).
But also to note, these 8.7 times figures (i.e. 9 times as the rough guide) are for a wheel that is already rotating. These speeds can be reduced to, in some cases, around 7.5 times for a stationary wheel. Hence the recommended Boeing technique on a wet/contaminated runway is for a firm touchdown to help increase the friction required to spin the wheel up (also the excuse I use on dry runways for my landings. "Sorry girls, Boeing recommended landing"..... :-) ).
If the aircraft only decellerated from 148kts to 79kts in the 5000ft available (69kts speed loss = 13.8kts per 1000ft) then surely it would have still overran if it had landed 3000ft earlier at the correct point?
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Actually, assuming an equal deceleration rate, it would require less runway.
consider: a vehicle decelarating from 200 m/s to 0 m/s at 10 m/s (roughly one G) decelaration.
In twenty seconds, it will stop, having travelled 2000 meters.
After ten seconds it will be going 100 m/s and have covered 1500 meters (average speed 150 m/s)
In ten more seconds, it have stopped. In the last ten seconds, it travels 500 meters.
So, in the example given, assuming an equal decelaration rate (which is probably not the case, since wheels tend to skid and hydroplane at higher speeds), it would need something like 1500 more feet.
consider: a vehicle decelarating from 200 m/s to 0 m/s at 10 m/s (roughly one G) decelaration.
In twenty seconds, it will stop, having travelled 2000 meters.
After ten seconds it will be going 100 m/s and have covered 1500 meters (average speed 150 m/s)
In ten more seconds, it have stopped. In the last ten seconds, it travels 500 meters.
So, in the example given, assuming an equal decelaration rate (which is probably not the case, since wheels tend to skid and hydroplane at higher speeds), it would need something like 1500 more feet.
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If the aircraft only decellerated from 148kts to 79kts in the 5000ft available (69kts speed loss = 13.8kts per 1000ft) then surely it would have still overran if it had landed 3000ft earlier at the correct point?
Touch Down 148 Kts.
Overrun at 79 kts.
Back of a fag packet type calculation, assuming contstant braking rate (a big assumption, but good enough for now...)
79^2 / 148^2 = .284
i.e. the a/c had 0.284 of its Kinetic Energy left, or had got rid of .716 of it in 5,000 feet.
5000 / .716 = about 7,000 feet, so it needed about 2,000 feet more.
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Air France at Toronto
UPDATED REPORT:
Both the BBC & ATI (Source of this article) are reporting the same thing so it seems possibly my concerns and fears may possibly be vidicated after all??
Early days yet!
Yes my congrates to the crew on getting everyone off safely however I hope the flight crew have updated their CV's to not including airline pilot!
ATI's Breaking Industry News Article
Crashed Air France A340 touched down halfway along runway (London)
Air Transport Intelligence news
David Kaminski-Morrow
Sun, 07 Aug 05 21:19:30 GMT
Initial flight-data recorder information has revealed that the Air France Airbus A340-300 destroyed last week after an overrun at Toronto Pearson airport had touched down nearly halfway along the runway.
Canada's Transportation Safety Board says that preliminary information indicates that the A340 landed some 4,000ft (1,220m) from the threshold of the 9,500ft runway 24L.
Chief investigator Real Levasseur, speaking today at a press conference, said given the wet conditions during the landing it would have been virtually impossible to stop the aircraft in the short space available.
"We're talking about nearly halfway down the runway [before the jet touched down]," said Levasseur. "Under those [wet-weather] conditions I'm pretty convinced that there's no way that the aircraft was going to be able to stop before the end of the runway."
He adds that the aircraft had touched down at around 148kts, slightly above the normal landing speed, probably owing to a slight tail-wind. The latest information showed the aircraft was travelling at 79kts when it left the runway.
"The pilots were fairly close to the speed that they should have been [at touchdown]," says Levasseur.
All 309 passengers and crew escaped the 2 August accident which occurred after the aircraft, arriving from Paris as flight 358, attempted to land during a thunderstorm.
After the aircraft came to rest in a ravine at the end of runway 24L, only four of the eight exit doors were used for the evacuation.
Levasseur says that the two left side aft doors - L3 and L4 - were never opened because cabin crew members considered the fire risk at these exits was too high.
"Flight attendants never opened [doors L3 and L4]," says Levasseur. "When they looked outside they saw fire on that side of the aircraft."
Door R3, behind the wing on the right side, was opened but the evacuation slide failed to deploy properly. A flight attendant also noticed a number of "sharp obstacles", says Levasseur, and opted to close the door again rather than use it for evacuation.
A fourth door - L2, just in front of the wing on the left side - popped open as the aircraft's fuselage suffered stresses during the overrun into the ravine. Some passengers left the aircraft through this exit.
Both the BBC & ATI (Source of this article) are reporting the same thing so it seems possibly my concerns and fears may possibly be vidicated after all??
Early days yet!
Yes my congrates to the crew on getting everyone off safely however I hope the flight crew have updated their CV's to not including airline pilot!
ATI's Breaking Industry News Article
Crashed Air France A340 touched down halfway along runway (London)
Air Transport Intelligence news
David Kaminski-Morrow
Sun, 07 Aug 05 21:19:30 GMT
Initial flight-data recorder information has revealed that the Air France Airbus A340-300 destroyed last week after an overrun at Toronto Pearson airport had touched down nearly halfway along the runway.
Canada's Transportation Safety Board says that preliminary information indicates that the A340 landed some 4,000ft (1,220m) from the threshold of the 9,500ft runway 24L.
Chief investigator Real Levasseur, speaking today at a press conference, said given the wet conditions during the landing it would have been virtually impossible to stop the aircraft in the short space available.
"We're talking about nearly halfway down the runway [before the jet touched down]," said Levasseur. "Under those [wet-weather] conditions I'm pretty convinced that there's no way that the aircraft was going to be able to stop before the end of the runway."
He adds that the aircraft had touched down at around 148kts, slightly above the normal landing speed, probably owing to a slight tail-wind. The latest information showed the aircraft was travelling at 79kts when it left the runway.
"The pilots were fairly close to the speed that they should have been [at touchdown]," says Levasseur.
All 309 passengers and crew escaped the 2 August accident which occurred after the aircraft, arriving from Paris as flight 358, attempted to land during a thunderstorm.
After the aircraft came to rest in a ravine at the end of runway 24L, only four of the eight exit doors were used for the evacuation.
Levasseur says that the two left side aft doors - L3 and L4 - were never opened because cabin crew members considered the fire risk at these exits was too high.
"Flight attendants never opened [doors L3 and L4]," says Levasseur. "When they looked outside they saw fire on that side of the aircraft."
Door R3, behind the wing on the right side, was opened but the evacuation slide failed to deploy properly. A flight attendant also noticed a number of "sharp obstacles", says Levasseur, and opted to close the door again rather than use it for evacuation.
A fourth door - L2, just in front of the wing on the left side - popped open as the aircraft's fuselage suffered stresses during the overrun into the ravine. Some passengers left the aircraft through this exit.
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The number of poor laymen´s comments and unprofessional and/or unfounded, merely speculative posts in this thread seems to have reached a new all-time high at PPRuNe. The constant quoting of equally ill-informed media sources does not help either...
I agree - but since PPRuNe has become a parody of itself, it's now subject to the same criticism which the media have had to (often unfairly) put up with from certain contributors to this forum.
Personally I'm not disappointed - this forum long ago became just a playground for immature schoolboy comments from people who simply spout generalised anti-media and anti-journalistic venom with the sort of unfounded, biased and ill-informed fundamentalism which wouldn't look out of place coming from certain radical clerics.
The more that PPRuNe's genuine, fair and reasonable contributors become engulfed and swamped by the speculative rantings of those who just want to slag off other professionals, the more likely it is that readers will turn away from PPRuNe and towards the aviation press in order to find authoritative, non-sensational information - without the amateurish cr@p.
Capt Pit Bull & DingerX - thanks for the explanation - It did cross my mind that it wasn't a linear relationship but good to get some actual numbers.
The worrying thing is that had the aircarft landed well within the 3,000ft touchdown zone (say 2,400ft in) it would have still gone off the end.
The worrying thing is that had the aircarft landed well within the 3,000ft touchdown zone (say 2,400ft in) it would have still gone off the end.
Doubt it. Anyone reading this thread can learn that the aircraft landed by the FO Deep on a very wet runway with a tailwind. Furthermore we have some figures and reasonable suppositions about braking distance required vs available.
As always you have to wait for the report. But this thread has far more content than I can read today in Flight or any other magazine or press article.
PPRuNe - its not as good as it was from day two.
Cheers
WWW
As always you have to wait for the report. But this thread has far more content than I can read today in Flight or any other magazine or press article.
PPRuNe - its not as good as it was from day two.
Cheers
WWW