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Who is saying that procedures allow one plane to take off when one is "3 miles out" or 65 seconds out at a very conservative estimate of a reasonable speed. Thi

Who is saying that procedures allow one plane to take off when one is "3 miles out" or 65 seconds out at a very conservative estimate of a reasonable speed. This isn't a lack of attention or coordination. He literally decided that one plane could take off in that space and repeatedly confirmed this decision.

hattmall 4y ago
That seems in line with what happens though. There's less than a minute, normally around 40 seconds between movements, a take off and landing. To casual observer it seems close of course but it appears the delay from the southwest crew was the issue. Then it's complicated by the lack of visibility from the tower because the controller couldn't detect the delay and issue appropriate commands.
- bagels 4y ago
  Nearly billion dollar jets and they can't slap a gps on them to see that they're sitting on the runway.
  - bigiain 4y ago
    I see aircraft (and even airport ground vehicles) on the runway all the time on my ADS-B setup. They 100% have them, just nobody was looking at them at the right time.
    - kqr 4y ago
      I find that in stressful and risky situations people stop trusting the data in front of them. They want to believe things are alright and will keep looking for new pieces of information to confirm that, while downplaying the importance of contradictory information.
      - moring 4y ago
        Do you know how true this is for (relatively) reliable systems such as those found in aviation? I know that in everyday life, what you say is absolutely true -- I definitely stop trusting electronic systems in stressful situations -- but then I also know how they feed me misleading as well as blatantly false data all the time, so I'd argue that not trusting them is not irrational per se.
        kqr 4y ago
        The way I understand it, it's not so much about the reliability of the electronics, but rather of human cognition. A lot of people have trouble believing that they (or other people in their custody) are on a trajectory to a fatal accident, so they instinctively reject evidence of this (not using their full brain due to stress response) and continue to search for evidence confirming that everything is alright.
  - paranoidrobot 4y ago
    The issue was not "Where were the aircraft". The controller knew where they were at all times. (And they do have GPS, They also have ADSB, and ground based position detection, and, and, and..)
    - bagels 4y ago
      Time 1:54, Tower: “Southwest 708, confirm on the roll?” They don't know if Southwest was moving?
      - hef19898 4y ago
        ATC is run by humans, planes are piloted by humans. The whole environment is highly controlled and regulated. And highly complex, and as this incident shows, one mistake in the whole chain, even a little one, can literally kill hundreds of people. This is nothing one can solve by throwing even more sensors and technology in, and have that run by ChatGPT or something. Highly trained people with the right amount and kind of technology are the solution. Edit: Sensors and stuff tell you were aircraft is, not what the human pilots are going to do when within the aloted period of time they have to do whatever they are cleared to do. Hence, you do the logical thing and ask them.
        account42 4y ago
        That humans are in charge of ATC and flying the planes doesn't mean that there can't be automation to assist them and cover mistakes. Poor visibility should not ever be a factor when we can have sensors that show exactly where the plane is on the ground. And yes we are definitely at a point where machine learning can predict the likely actions based on the human communication and warn if the predicted path could lead to a collision. The point is to have multiple safty systems (inclduing the human operators) so that one mistake doesn't kill hundreds of people because there are secondary systems to catch it.
      - paranoidrobot 4y ago
        The aircraft were at all relevant times broadcasting their position using ADSB. The controller had at least one screen displaying their positionx probably several. It may fuse multiple data sources. They may also have been able to see the Southwest aircraft, although maybe not clearly or only as lights. Despite this it can be difficult to judge the speed of an object at long distances under less than ideal circumstances and at night without a long observation period. So yeah they knew where they were but not the acceleration. It's also worth pointing out that the controller may have been in sudden stress due to realising the aircraft were too close, and so may have made a call that they already knew the answer to.
kcg 4y ago
> Who is saying that procedures allow one plane to take off when one is "3 miles out" The FAA says that, specifically the 7110.65 which governs ATC rules and procedures. In a radar environment it allows for departures when the arriving aircraft is 2+ miles from the runway, and there will be at least 3 miles of separation within 1 min of takeoff. A separate rule requires that the departing aircraft is at least 6000ft down the runway and airborne before the arrival crosses the runway threshold. If there is a departing plane rolling up to the hold short line and confirmed ready for immediate takeoff, there is possibly time to get them out and maintain separation. If it's low visibility, the departing plane is rolling slowly and not confirmed ready, then it's a bad bad idea.
- cameldrv 4y ago
  I think that's generally correct, but I'm not familiar with all of the rules. That said, even if the Southwest plane had been faster on the runway, they weren't going to be able to maintain 6000 feet of separation. If Southwest starts rolling from a dead stop, and Fedex is barreling in at 140 knots from two miles, they're necessarily going to converge until Southwest accelerates, which takes a minute. Juan Brown [1] made an interesting point also. For a Cat II or III approach, and this one was definitely Cat III, there is an ILS critical area that Southwest would have impinged on as it was taking off. The controller very clearly made a huge mistake. [1]https://www.youtube.com/watch?v=SvUOHa8n7aQ https://www.youtube.com/watch?v=SvUOHa8n7aQ
- michaelmrose 4y ago
  It says there can be as little as 2 miles of separation which I read as 2 miles when the wheels lift off begining acceleration would end up with 0 ft of separation.
  - kcg 4y ago
    The rules specifically state how 2 miles of separation is defined. 7110.65 5-8-4-Note 1 says "This procedure permits a departing aircraft to be released so long as an arriving aircraft is no closer than 2 miles from the runway at the time. This separation is determined at the time the departing aircraft commences takeoff roll." [1] Just to keep stating this: I'm not at all defending the AUS controller here. A squeeze play like this in low visibility is needlessly reckless. [1] https://www.faa.gov/air_traffic/publications/atpubs/atc_html/chap5_section_8.html https://www.faa.gov/air_traffic/publications/atpubs/atc_html...

hattmall 4y ago

That seems in line with what happens though. There's less than a minute, normally around 40 seconds between movements, a take off and landing. To casual observer it seems close of course but it appears the delay from the southwest crew was the issue. Then it's complicated by the lack of visibility from the tower because the controller couldn't detect the delay and issue appropriate commands.

bagels 4y ago
Nearly billion dollar jets and they can't slap a gps on them to see that they're sitting on the runway.
- bigiain 4y ago
  I see aircraft (and even airport ground vehicles) on the runway all the time on my ADS-B setup. They 100% have them, just nobody was looking at them at the right time.
  - kqr 4y ago
    I find that in stressful and risky situations people stop trusting the data in front of them. They want to believe things are alright and will keep looking for new pieces of information to confirm that, while downplaying the importance of contradictory information.
    - moring 4y ago
      Do you know how true this is for (relatively) reliable systems such as those found in aviation? I know that in everyday life, what you say is absolutely true -- I definitely stop trusting electronic systems in stressful situations -- but then I also know how they feed me misleading as well as blatantly false data all the time, so I'd argue that not trusting them is not irrational per se.
      - kqr 4y ago
        The way I understand it, it's not so much about the reliability of the electronics, but rather of human cognition. A lot of people have trouble believing that they (or other people in their custody) are on a trajectory to a fatal accident, so they instinctively reject evidence of this (not using their full brain due to stress response) and continue to search for evidence confirming that everything is alright.
- paranoidrobot 4y ago
  The issue was not "Where were the aircraft". The controller knew where they were at all times. (And they do have GPS, They also have ADSB, and ground based position detection, and, and, and..)
  - bagels 4y ago
    Time 1:54, Tower: “Southwest 708, confirm on the roll?” They don't know if Southwest was moving?
    - hef19898 4y ago
      ATC is run by humans, planes are piloted by humans. The whole environment is highly controlled and regulated. And highly complex, and as this incident shows, one mistake in the whole chain, even a little one, can literally kill hundreds of people. This is nothing one can solve by throwing even more sensors and technology in, and have that run by ChatGPT or something. Highly trained people with the right amount and kind of technology are the solution. Edit: Sensors and stuff tell you were aircraft is, not what the human pilots are going to do when within the aloted period of time they have to do whatever they are cleared to do. Hence, you do the logical thing and ask them.
      - account42 4y ago
        That humans are in charge of ATC and flying the planes doesn't mean that there can't be automation to assist them and cover mistakes. Poor visibility should not ever be a factor when we can have sensors that show exactly where the plane is on the ground. And yes we are definitely at a point where machine learning can predict the likely actions based on the human communication and warn if the predicted path could lead to a collision. The point is to have multiple safty systems (inclduing the human operators) so that one mistake doesn't kill hundreds of people because there are secondary systems to catch it.
    - paranoidrobot 4y ago
      The aircraft were at all relevant times broadcasting their position using ADSB. The controller had at least one screen displaying their positionx probably several. It may fuse multiple data sources. They may also have been able to see the Southwest aircraft, although maybe not clearly or only as lights. Despite this it can be difficult to judge the speed of an object at long distances under less than ideal circumstances and at night without a long observation period. So yeah they knew where they were but not the acceleration. It's also worth pointing out that the controller may have been in sudden stress due to realising the aircraft were too close, and so may have made a call that they already knew the answer to.

kcg 4y ago

> Who is saying that procedures allow one plane to take off when one is "3 miles out" The FAA says that, specifically the 7110.65 which governs ATC rules and procedures. In a radar environment it allows for departures when the arriving aircraft is 2+ miles from the runway, and there will be at least 3 miles of separation within 1 min of takeoff. A separate rule requires that the departing aircraft is at least 6000ft down the runway and airborne before the arrival crosses the runway threshold. If there is a departing plane rolling up to the hold short line and confirmed ready for immediate takeoff, there is possibly time to get them out and maintain separation. If it's low visibility, the departing plane is rolling slowly and not confirmed ready, then it's a bad bad idea.

cameldrv 4y ago
I think that's generally correct, but I'm not familiar with all of the rules. That said, even if the Southwest plane had been faster on the runway, they weren't going to be able to maintain 6000 feet of separation. If Southwest starts rolling from a dead stop, and Fedex is barreling in at 140 knots from two miles, they're necessarily going to converge until Southwest accelerates, which takes a minute. Juan Brown [1] made an interesting point also. For a Cat II or III approach, and this one was definitely Cat III, there is an ILS critical area that Southwest would have impinged on as it was taking off. The controller very clearly made a huge mistake. [1]https://www.youtube.com/watch?v=SvUOHa8n7aQ https://www.youtube.com/watch?v=SvUOHa8n7aQ
michaelmrose 4y ago
It says there can be as little as 2 miles of separation which I read as 2 miles when the wheels lift off begining acceleration would end up with 0 ft of separation.
- kcg 4y ago
  The rules specifically state how 2 miles of separation is defined. 7110.65 5-8-4-Note 1 says "This procedure permits a departing aircraft to be released so long as an arriving aircraft is no closer than 2 miles from the runway at the time. This separation is determined at the time the departing aircraft commences takeoff roll." [1] Just to keep stating this: I'm not at all defending the AUS controller here. A squeeze play like this in low visibility is needlessly reckless. [1] https://www.faa.gov/air_traffic/publications/atpubs/atc_html/chap5_section_8.html https://www.faa.gov/air_traffic/publications/atpubs/atc_html...