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They actually do clearly state in this PDF that a degree of fault lies in the crew being compromised by fatigue. Operating for 19 hours straight definitely plac

They actually do clearly state in this PDF that a degree of fault lies in the crew being compromised by fatigue. Operating for 19 hours straight definitely places an individual in an area where one can be fighting to pay strict attention, even when it really counts. There's also plenty of communication with Air Traffic Control in the tower, and not a whole lot of gaps to introduce significant mystery, so it's pretty unlikely that there would be anything earth shattering on the cockpit voice recorder.

tialaramex 8y ago
What I'd expect the CVR to provide good evidence of is the extent to which crew were actually doing the checks that should have caught this error, and their reaction when they belatedly discovered their true position. Without even trying to mislead investigators a human will report a sanitised version of events when not cued by facts. "Then I scratched my arse and sniffed my finger" is not going to appear in this sanitised version of events even if true. Neither is "I glanced at the panel, I know I'm supposed to scan it, but usually anything important flashes red". The tower log helps, CVR is better, and CCTV better again. It also really helps to get into the routine of analysing this stuff. If your aircrew routinely skip steps 4, 18 and 23 from the checklist, only finding that out when 200 passengers die in a crash is stupid. Let's find out now. That needs lots of heavy lifting, pilots have to trust the airlines not to fire them for ordinary human frailties, and airlines have to accept that their pilots are human and "But the manual says not to do that" doesn't make it stop happening magically. You're right that fatigue is an obvious element here, and there are several technical countermeasures mentioned. I definitely don't want to come across as believing in a conspiracy to hide the facts, but on the other hand I struggle to believe that it took over 30 minutes to get this thing back down after the incident and so the overwrite was not a decision. And if we agree it was a decision, it was a seriously bad one that should not be repeated.
- cpitVoxRec 8y ago
  I struggle to believe that it took over 30 minutes to get this thing back down after the incident If your inferring that a 30 minute offset was introduced, in order to dump the stale audio buffer, before permitting access to the CVR instrument on the ground, I'd offer the idea that there were 4 other planes on the taxiway, waiting to take off, and that the intervening 30 minutes could be eaten up by letting those planes depart, based on an array of other factors. A concerted effort to dump the recorder buffer would require the participation of more than just the flight crew, since it manipulates the standing traffic pattern. Not an impossibility, and we know that in-group "walls of silence" definitely accumulate in high-intensity industries, but the air traffic control audio suggests a really minor transgression of situational awareness, even if the circumstances are assuredly unforgiving ones. In the radio audio, the pilot clearly states that he's noticing lights on what he imagines to be his runway, and asks for confirmation as to what they might be. The tower reaffirms that he's all clear. Only then does a pilot from one of the planes on the ground speak up, and complain. At that moment, both ATC and the plane realize the error. It's arguable that the pilot anticipated a likely go-around, based on intuition that the lights he was observing were definitely other planes, and that what appears to be an extremely close call proves it's own margin of error as reasonable, given that the participants recovered from the error.
  - tialaramex 8y ago
    No, I'm _implying_ that I don't believe it took 30 minutes to get down. Based on the abstract I would say you're going to find out it came back down in under 30 minutes, and then "oops" they let the CVR be re-used, overwriting the recording anyway. The text from the linked abstract says: "Cockpit voice recorder (CVR) information was not available for this incident because the data were overwritten before senior Air Canada officials became aware of the severity of this incident" One of the nice things about working in the Web PKI is that this crap doesn't get you anywhere since keeping records is one of the requirements, and any time the options are "This issuer might be crooked or they might be incompetent" both are disqualifiying anyway, no need to figure out which it is to make a determination. It lets me sleep easier, were people at Symantec reckless, or were they so greedy that they actively tolerated fraud? Don't care, not my problem now, let their shareholders worry about it.
    - deleted 8y ago
      [deleted]
    - cpitVoxRec 8y ago
      Oh, I don't know about these particular ideas you're chasing. There are quite a number of independent, redundant resources that would be very difficult to align forgeries across and present as fraudulent data, worldwide, for weeks, months, and even years after the incident. It just sounds like a fishing expedition for some kind of cover up that exploits an incredibly narrow gap, covered by a myriad of alternative information sources that are more than capable of sealing up an air tight sequence of events by other means. Open, consumer information sources like flightaware.com alone had the answer to the questions you're asking, long ago. The radar history for this event was paywalled here for days after the event: https://flightaware.com/live/flight/ACA759/history https://flightaware.com/live/flight/ACA759/history The open, freebie log only gives like two weeks of charts, but the data you mention was lying around, available for like 8 months, to anyone with premium access to that particular service. And anyway, I'm sure it's just a convenience wrapper to public data that's still floating around to anyone willing to dig. Here's another service, if you've got $500 bucks, and really would like to know right now: https://www.flightradar24.com/data/flights/ac759/ https://www.flightradar24.com/data/flights/ac759/ And to reiterate, this is only costing money today on account of being late to the party. Multiple systems surfaced this data to the world in real time, and openly back-logged for months after. I'd bet good money a wide audience fact checked exactly what you've suggested a long time ago (even here: https://news.ycombinator.com/item?id=14741605 https://news.ycombinator.com/item?id=14741605). But my opinion isn't very important when the information is available in a general sense, to anyone who really wants it, even now, more than a year later. Feel free to be suspicious about these resources being far downstream and non-official consumer products, but if that doesn't suffice, then other (much, much bigger) doubts occlude any potentially satisfactory assessment which won't get solved in a random thread by amateur internet detectives like us.
PhantomGremlin 8y ago
Operating for 19 hours straight Nobody was operating for that length of time. The captain had been awake for 19 hours, the first officer had been awake for 12 hours. Granted, most people can't function anywhere near their peak performance after being awake for 19 hours. Also there's not enough information in the summary to know the captain's recent history; how much rest time did he have before that flight?
- cpitVoxRec 8y ago
  To call attention to my use of the word "operating" in this context, and highlight strict use of the word as ...technical(?) vocabulary, to form a rationale for censure of the general thrust of my statement, is pretty pedantic, and a semantic criticism at best. Nonetheless, I'll put forward, that even if a direct flight from Toronto to San Francisco only takes about 5 or 6 hours, 19 hours, and rounding out the time of day to midnight as a circadian cue, definitely puts the pilot 3 hours past the usual 16 hour limit for bedtime (right, 12 hours for the co-pilot, okay). Both the pilot and co-pilot probably had at minimum another entire hour before they'd even have a chance to wind down and turn in for the night, so pile up the anticipatory nature of having to deplane and get to a hotel room onto their psychological state.

tialaramex 8y ago

What I'd expect the CVR to provide good evidence of is the extent to which crew were actually doing the checks that should have caught this error, and their reaction when they belatedly discovered their true position. Without even trying to mislead investigators a human will report a sanitised version of events when not cued by facts. "Then I scratched my arse and sniffed my finger" is not going to appear in this sanitised version of events even if true. Neither is "I glanced at the panel, I know I'm supposed to scan it, but usually anything important flashes red". The tower log helps, CVR is better, and CCTV better again. It also really helps to get into the routine of analysing this stuff. If your aircrew routinely skip steps 4, 18 and 23 from the checklist, only finding that out when 200 passengers die in a crash is stupid. Let's find out now. That needs lots of heavy lifting, pilots have to trust the airlines not to fire them for ordinary human frailties, and airlines have to accept that their pilots are human and "But the manual says not to do that" doesn't make it stop happening magically. You're right that fatigue is an obvious element here, and there are several technical countermeasures mentioned. I definitely don't want to come across as believing in a conspiracy to hide the facts, but on the other hand I struggle to believe that it took over 30 minutes to get this thing back down after the incident and so the overwrite was not a decision. And if we agree it was a decision, it was a seriously bad one that should not be repeated.

cpitVoxRec 8y ago
I struggle to believe that it took over 30 minutes to get this thing back down after the incident If your inferring that a 30 minute offset was introduced, in order to dump the stale audio buffer, before permitting access to the CVR instrument on the ground, I'd offer the idea that there were 4 other planes on the taxiway, waiting to take off, and that the intervening 30 minutes could be eaten up by letting those planes depart, based on an array of other factors. A concerted effort to dump the recorder buffer would require the participation of more than just the flight crew, since it manipulates the standing traffic pattern. Not an impossibility, and we know that in-group "walls of silence" definitely accumulate in high-intensity industries, but the air traffic control audio suggests a really minor transgression of situational awareness, even if the circumstances are assuredly unforgiving ones. In the radio audio, the pilot clearly states that he's noticing lights on what he imagines to be his runway, and asks for confirmation as to what they might be. The tower reaffirms that he's all clear. Only then does a pilot from one of the planes on the ground speak up, and complain. At that moment, both ATC and the plane realize the error. It's arguable that the pilot anticipated a likely go-around, based on intuition that the lights he was observing were definitely other planes, and that what appears to be an extremely close call proves it's own margin of error as reasonable, given that the participants recovered from the error.
- tialaramex 8y ago
  No, I'm _implying_ that I don't believe it took 30 minutes to get down. Based on the abstract I would say you're going to find out it came back down in under 30 minutes, and then "oops" they let the CVR be re-used, overwriting the recording anyway. The text from the linked abstract says: "Cockpit voice recorder (CVR) information was not available for this incident because the data were overwritten before senior Air Canada officials became aware of the severity of this incident" One of the nice things about working in the Web PKI is that this crap doesn't get you anywhere since keeping records is one of the requirements, and any time the options are "This issuer might be crooked or they might be incompetent" both are disqualifiying anyway, no need to figure out which it is to make a determination. It lets me sleep easier, were people at Symantec reckless, or were they so greedy that they actively tolerated fraud? Don't care, not my problem now, let their shareholders worry about it.
  - deleted 8y ago
    [deleted]
  - cpitVoxRec 8y ago
    Oh, I don't know about these particular ideas you're chasing. There are quite a number of independent, redundant resources that would be very difficult to align forgeries across and present as fraudulent data, worldwide, for weeks, months, and even years after the incident. It just sounds like a fishing expedition for some kind of cover up that exploits an incredibly narrow gap, covered by a myriad of alternative information sources that are more than capable of sealing up an air tight sequence of events by other means. Open, consumer information sources like flightaware.com alone had the answer to the questions you're asking, long ago. The radar history for this event was paywalled here for days after the event: https://flightaware.com/live/flight/ACA759/history https://flightaware.com/live/flight/ACA759/history The open, freebie log only gives like two weeks of charts, but the data you mention was lying around, available for like 8 months, to anyone with premium access to that particular service. And anyway, I'm sure it's just a convenience wrapper to public data that's still floating around to anyone willing to dig. Here's another service, if you've got $500 bucks, and really would like to know right now: https://www.flightradar24.com/data/flights/ac759/ https://www.flightradar24.com/data/flights/ac759/ And to reiterate, this is only costing money today on account of being late to the party. Multiple systems surfaced this data to the world in real time, and openly back-logged for months after. I'd bet good money a wide audience fact checked exactly what you've suggested a long time ago (even here: https://news.ycombinator.com/item?id=14741605 https://news.ycombinator.com/item?id=14741605). But my opinion isn't very important when the information is available in a general sense, to anyone who really wants it, even now, more than a year later. Feel free to be suspicious about these resources being far downstream and non-official consumer products, but if that doesn't suffice, then other (much, much bigger) doubts occlude any potentially satisfactory assessment which won't get solved in a random thread by amateur internet detectives like us.

PhantomGremlin 8y ago

Operating for 19 hours straight Nobody was operating for that length of time. The captain had been awake for 19 hours, the first officer had been awake for 12 hours. Granted, most people can't function anywhere near their peak performance after being awake for 19 hours. Also there's not enough information in the summary to know the captain's recent history; how much rest time did he have before that flight?

cpitVoxRec 8y ago
To call attention to my use of the word "operating" in this context, and highlight strict use of the word as ...technical(?) vocabulary, to form a rationale for censure of the general thrust of my statement, is pretty pedantic, and a semantic criticism at best. Nonetheless, I'll put forward, that even if a direct flight from Toronto to San Francisco only takes about 5 or 6 hours, 19 hours, and rounding out the time of day to midnight as a circadian cue, definitely puts the pilot 3 hours past the usual 16 hour limit for bedtime (right, 12 hours for the co-pilot, okay). Both the pilot and co-pilot probably had at minimum another entire hour before they'd even have a chance to wind down and turn in for the night, so pile up the anticipatory nature of having to deplane and get to a hotel room onto their psychological state.