Air Canada A320 accident at Halifax
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MD88s and RNP?
The MD88s FMSs could have likely had RNP at the time... but for an initial operator opting out in discussions with the (former) OEM. Same happened to the original MD11s, and their still RNP challenged and potentially problematic VNAV.
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It is said that the FO did not see the PAPIs... Could it be, that with a large crab angle, the pilot could also not see the PAPIs, as they could have been obscured by the nose of the A320?
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phiggsbroadband
Are you talking about AC624 and if so where did you hear that information?
If the F/O could not see the PAPIs then it is likely that they were off/broken/obscured.
Are you talking about AC624 and if so where did you hear that information?
If the F/O could not see the PAPIs then it is likely that they were off/broken/obscured.
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Either that or their forward view was being obscured by the LOC antennas..
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Tom Imrich:
Perhaps it was after you departed the FAA, but they have had for some time the glide-slope qualification surface (GQS). If the GQS is penetrated then the runway is disqualified from having any approach with vertical guidance, whether it be ILS, GLS, LNAV/VNAV, RNP AR, or LPV. Then there is the FAA's visual segment, which is wider than the GQS, and which every approach has. The visual segment can have obstacles but only to a point. That became much stricter after the Lear hit the trees one night.
Also, the cost of converting a large fleet's FMS and avionics to RNP AR feathering to GLS would be huge. (many of those approaches would have to be "dual string" because of low RNP requirements.) You know that Boeing, for one major OEM, charges an arm, leg, and your first born child to make such modifications.
Finally, there are airports where decent minimums cannot be obtained because of significant terrain in the missed approach segment. Related to that, the commercial operator has to also have a viable OEI path for the missed approach.
BTW, have you flown LPV? It is a great system where it can be sited. The accident runway at Halifax has a great LPV approach but apparently the airline wanted to keep their first born child.
It is time to move on, to 100% RNP and GLS, globally. Then we'll finally see these unnecessarily hull losses abate.
Also, the cost of converting a large fleet's FMS and avionics to RNP AR feathering to GLS would be huge. (many of those approaches would have to be "dual string" because of low RNP requirements.) You know that Boeing, for one major OEM, charges an arm, leg, and your first born child to make such modifications.
Finally, there are airports where decent minimums cannot be obtained because of significant terrain in the missed approach segment. Related to that, the commercial operator has to also have a viable OEI path for the missed approach.
BTW, have you flown LPV? It is a great system where it can be sited. The accident runway at Halifax has a great LPV approach but apparently the airline wanted to keep their first born child.
737er:
86000 views for what could have prevented for a few thousand bucks on an ILS and relocation of power lines...a lesson that could be used all over to improve safety.
Over 3 million views for a fluke occurance that's basicallly unpreventable.
Meanwhile, bombs threats on Turkish, passengers storming the cockpit on United.....on and on.
But the problem is suicidal pilots. It's amazing.
86000 views for what could have prevented for a few thousand bucks on an ILS and relocation of power lines...a lesson that could be used all over to improve safety.
Over 3 million views for a fluke occurance that's basicallly unpreventable.
Meanwhile, bombs threats on Turkish, passengers storming the cockpit on United.....on and on.
But the problem is suicidal pilots. It's amazing.
Suicide, a vanishing airliner, a CAVU prang at a major airport, etc will always have more interest than say a night, bad weather cras....sorry, heavy landing....without a fatality any day. Rather more routine.
Incidentally, am I reading this Actual right, or is this a typo:
CYHZ 290400Z 34019G54KT 3/4SM R14/5000VP6000FT/D -SN DRSN BKN007
????
If that's correct, it's one hell of a gust factor!
Yes it is indeed, if true. I am a retired professional meteorologist, and such factors as about 2.8 are, as pilots will know, very rare but possibly associated with thunderstorms or indeed city centres. Very unlikely that anyone would write it in a TAF, for example.
CYHZ 290400Z 34019G54KT 3/4SM R14/5000VP6000FT/D -SN DRSN BKN007
????
If that's correct, it's one hell of a gust factor!
Yes it is indeed, if true. I am a retired professional meteorologist, and such factors as about 2.8 are, as pilots will know, very rare but possibly associated with thunderstorms or indeed city centres. Very unlikely that anyone would write it in a TAF, for example.
Last edited by langleybaston; 31st Mar 2015 at 15:17. Reason: error
UK Met Office Handbook says:
Table 6.4(a). Ratio of maximum (3-second) gust to mean hourly speed (for
strong, steady 10 m winds)
Surface type, Range of Estimated
ratios, average
Open sea 1.3, 1.3
Isolated hill tops 1.4-1.5, 1.4
Flat open country 1.4-1.8, 1.6
*Rolling country (few wind-breaks) 1.5-2.0, 1.7
Rolling country (numerous wind-breaks),
forest areas, towns, outskirts of large cities 1.7-2.1, 1.9
Centres of large cities 1.9-2.3, 2.1
Local variations, using this commonly used category, often give gusts varying widely in space and time from the estimated values, making airfield forecasting difficult, especially under isallobaric surging.
Table 6.4(a). Ratio of maximum (3-second) gust to mean hourly speed (for
strong, steady 10 m winds)
Surface type, Range of Estimated
ratios, average
Open sea 1.3, 1.3
Isolated hill tops 1.4-1.5, 1.4
Flat open country 1.4-1.8, 1.6
*Rolling country (few wind-breaks) 1.5-2.0, 1.7
Rolling country (numerous wind-breaks),
forest areas, towns, outskirts of large cities 1.7-2.1, 1.9
Centres of large cities 1.9-2.3, 2.1
Local variations, using this commonly used category, often give gusts varying widely in space and time from the estimated values, making airfield forecasting difficult, especially under isallobaric surging.
One problem is conducting the visual segment
My apologies for failing to notice there is indeed a PAPI at the runway. Why it didn't provide the essential vertical path cues, I don't understand.
ILS, LOC, NBD, RNP AR etc, may have their contribution, no doubt. But if there is a visual segment - an MDA, DA/DH - then the pilot still has to land visually.
I won't try to conclude what exactly went wrong - but it has to do with flying the visual segment - or choosing not to and going around. I am afraid that except for autoland, the safety of the instrument approach absolutely depends on this point.
Challenging wind conditions, lousy visibility conditions, no doubt. You still must have ALL the criteria met for descent and operation below the decision altitude.
ILS, LOC, NBD, RNP AR etc, may have their contribution, no doubt. But if there is a visual segment - an MDA, DA/DH - then the pilot still has to land visually.
I won't try to conclude what exactly went wrong - but it has to do with flying the visual segment - or choosing not to and going around. I am afraid that except for autoland, the safety of the instrument approach absolutely depends on this point.
Challenging wind conditions, lousy visibility conditions, no doubt. You still must have ALL the criteria met for descent and operation below the decision altitude.
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You know that Boeing, for one major OEM, charges an arm, leg, and your first born child to make such modifications.
We have GBAS capability since 2006 on our boeings (and those have RNP 0.1 as well) and when the decision was made to phase out the boeings in favour of airbii one of the questions was how much it would cost to install GBAS on them. But with around 250k per airframe for a narrowbody airbus there simply wasn't a business case. However, we have to start getting RNP AR approval now, previously we could simply boeings only on those limiting flights.
@ GlobalNav...
My apologies for failing to notice there is indeed a PAPI at the runway. Why it didn't provide the essential vertical path cues, I don't understand
Perhaps it was out of service, or it was not switched "ON" or with all that snow, drifting snow with the strong winds maybe it was covered it up.
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PAPI
"Perhaps it was out of service, or it was not switched "ON" or with all that snow, drifting snow with the strong winds maybe it was covered up"
A somewhat amusing image: Papy couldn't get out to clear the PAPI.
There's one hell of a disconnect between the cababilities of a $100m plane and that of the airport
A somewhat amusing image: Papy couldn't get out to clear the PAPI.
There's one hell of a disconnect between the cababilities of a $100m plane and that of the airport
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Could not see papis ?
Found this on American TV network abcnews.com. Text says that the aircraft TOUCHED DOWN 1100 feet short of the runway. If accurate, would that not put the aircraft below the line of sight to the papis?
Officials Examining Why Plane Landed Short of Halifax Runway - ABC News
Officials Examining Why Plane Landed Short of Halifax Runway - ABC News
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"... says that the aircraft TOUCHED DOWN 1100 feet short of the runway. If accurate, would that not put the aircraft below the line of sight to the papis?"
Exactly.
The point 1100 ft short, where the AC first hit the ground, is actually BELOW the level of the end of the runway. That's why it hit the power lines.
Exactly.
The point 1100 ft short, where the AC first hit the ground, is actually BELOW the level of the end of the runway. That's why it hit the power lines.
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Yes, the aircraft first hit in an area that is actually about 40' BELOW the runway elevation.
From there they went through a power line, continued across a road, and then up a hill where they hit the localizer antenna. They continued up the hill and onto the runway.
https://www.google.ca/maps/@44.86373...UmLyZZONTA!2e0
From there they went through a power line, continued across a road, and then up a hill where they hit the localizer antenna. They continued up the hill and onto the runway.
https://www.google.ca/maps/@44.86373...UmLyZZONTA!2e0
Last edited by Lost in Saigon; 1st Apr 2015 at 01:37.
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Good to hear from you aterpster!!!... All good and partially valid points, ...but there are still reasonable and useful low cost and high capability ways forward, with both RNP and GLS.
First, there are vastly better ways to do the GQS than FAA did, just as we did with many "near in" issues at [real] RNP sites. If an aircraft can safely operate visually at all, then there are ways to do both real RNP, as well as to even qualify the runway for using LAND 3/AIII or equivalent through rollout, as well as addressing safe OEI balked landing protection from the TDZ. There are VERY few true and real "one way" in and out runways globally, which may need to use an explicit commit point. As to cost, neither GLS nor RNP needs to be expensive. They are presently only priced the way they are for largely non-technical commercial reasons, that the marketplace could easily solve, and likely will eventually solve.
Yes, I've flown LPV, as well as FLS and IAN,... (extensively) as well as nearly every other All-WX-Ops idea (good or bad) from the days dating back to the '60s. Col. Carl Crane and I even discussed it back in '73, while flying with him at Wright Field, with a demo of his "All-Weather-Flight-Gage" dating back to the '30s! So while LPV might have been a reasonable idea back in the period of 1969 through '71, at the advent of autoflight systems like the SPZ-1, PB-100, or FCS-110, and the related nav systems like the TERN-100 and AINS-70, ...LPV is still obsolete trapezoidal, angular, straight-in, and horrendously airspace wasting criteria. As a concept, it no longer makes any sense at all, since we first first did linear RNP .15 around the corners at KEGE back in 1991, and later at the first real "published" formal RNP at PAJN in 1994. RNP is ALWAYS better, safer, more usable, and a better long term solution than any LPV (especially when combined with GLS/GBAS). RNP could have been (and still could) be done for FAR LESS COST and far more benefit than WAAS/LPV, for everyone from tiny UAVs, to GA, to the largest wide body's and DoD vehicles. Unfortunately, it was largely AVN, AIR-130, and later AFS-400 that set GA on this foolish course, with having had no vision, or credible experience, or technical capability, or understanding of the true system and operations level risks involved whatsoever (versus their naive and seriously limited and flawed CRM assessments) ...that screwed this subject all up for over two decades for nearly all the world. So now WAAS(SBAS)/LPV is an entirely obsolete waste of money for everyone, with a lost generation of avionics that will never solve NextGen economically, safely, or efficiently, that needs to simply be phased out at the earliest opportunity, before it further fouls up major portions of global airspace and ANSPs. When we're already landing "critical risk to ship" UAVs on pitching rolling moving decks within 1 ft laterally, and 8 ft longitudinally with these concepts or equivalent, while safely and routinely missing nearby obstructions by a few feet, as well as safely and softly landing other UAVs for pennies per landing (with systems like Portabas), ...then still continuing to unnecessarily lose A320s at CYHZ, or A330s at VNKT, or B777s at KSFO is absurd.
First, there are vastly better ways to do the GQS than FAA did, just as we did with many "near in" issues at [real] RNP sites. If an aircraft can safely operate visually at all, then there are ways to do both real RNP, as well as to even qualify the runway for using LAND 3/AIII or equivalent through rollout, as well as addressing safe OEI balked landing protection from the TDZ. There are VERY few true and real "one way" in and out runways globally, which may need to use an explicit commit point. As to cost, neither GLS nor RNP needs to be expensive. They are presently only priced the way they are for largely non-technical commercial reasons, that the marketplace could easily solve, and likely will eventually solve.
Yes, I've flown LPV, as well as FLS and IAN,... (extensively) as well as nearly every other All-WX-Ops idea (good or bad) from the days dating back to the '60s. Col. Carl Crane and I even discussed it back in '73, while flying with him at Wright Field, with a demo of his "All-Weather-Flight-Gage" dating back to the '30s! So while LPV might have been a reasonable idea back in the period of 1969 through '71, at the advent of autoflight systems like the SPZ-1, PB-100, or FCS-110, and the related nav systems like the TERN-100 and AINS-70, ...LPV is still obsolete trapezoidal, angular, straight-in, and horrendously airspace wasting criteria. As a concept, it no longer makes any sense at all, since we first first did linear RNP .15 around the corners at KEGE back in 1991, and later at the first real "published" formal RNP at PAJN in 1994. RNP is ALWAYS better, safer, more usable, and a better long term solution than any LPV (especially when combined with GLS/GBAS). RNP could have been (and still could) be done for FAR LESS COST and far more benefit than WAAS/LPV, for everyone from tiny UAVs, to GA, to the largest wide body's and DoD vehicles. Unfortunately, it was largely AVN, AIR-130, and later AFS-400 that set GA on this foolish course, with having had no vision, or credible experience, or technical capability, or understanding of the true system and operations level risks involved whatsoever (versus their naive and seriously limited and flawed CRM assessments) ...that screwed this subject all up for over two decades for nearly all the world. So now WAAS(SBAS)/LPV is an entirely obsolete waste of money for everyone, with a lost generation of avionics that will never solve NextGen economically, safely, or efficiently, that needs to simply be phased out at the earliest opportunity, before it further fouls up major portions of global airspace and ANSPs. When we're already landing "critical risk to ship" UAVs on pitching rolling moving decks within 1 ft laterally, and 8 ft longitudinally with these concepts or equivalent, while safely and routinely missing nearby obstructions by a few feet, as well as safely and softly landing other UAVs for pennies per landing (with systems like Portabas), ...then still continuing to unnecessarily lose A320s at CYHZ, or A330s at VNKT, or B777s at KSFO is absurd.
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I think this is a more compelling incident than the Germanwings crash. This has a larger bearing on how we operate the Airbus. I will be very interested in the final report from the TSB to see what they set for FPA, when they started down from the FAF, or even if they inadvertently started down before the FAF.
People here have questioned why they didn't use the PAPi. With a half mile of visibility even on the proper descent angle to the runway it would have been difficult. At a 3 degree glide path 300' above field elevation puts you a mile out. PAPis are usually about 500' down from the end of the runway. So that's just over a mile from the missed approach point to the PAPi. Hard to pick up with blowing precipitation.
People here have questioned why they didn't use the PAPi. With a half mile of visibility even on the proper descent angle to the runway it would have been difficult. At a 3 degree glide path 300' above field elevation puts you a mile out. PAPis are usually about 500' down from the end of the runway. So that's just over a mile from the missed approach point to the PAPi. Hard to pick up with blowing precipitation.