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It's strange that the planes were supposed to be flying parallel and yet the damage to both planes in the photos suggests a collision at right angles Remarkabl

It's strange that the planes were supposed to be flying parallel and yet the damage to both planes in the photos suggests a collision at right angles Remarkable that the Metroliner held together, despite that terrible damage, and they landed it safely edit: interesting photo of the landing from the Reddit thread linked elsewhere https://imgur.com/gallery/yKPOWR0 https://imgur.com/gallery/yKPOWR0

t0mas88 5y ago
The Cirrus overshot the centerline of the runway it was supposed to land on. The common way for these situations is for the plane to be on an intercept angle towards the centerline. That's a max 30 degree angle for an instrument approach, but this was a visual approach so it could have been a sharper angle. All it takes to make this mistake in a Cirrus (and other G1000 avionics type small airplanes) is to forget 1 button on the autopilot mode. If it isn't set to capture the final approach track (either GPS or ILS) it will continue straight ahead which in this case means into the side of another airplane. One thing that makes it more likely is that US air traffic control makes heavy use of visual approaches, and then it's allowed to point two aircraft at collision courses on the same altitude because they can see each other. The European way to do this is to have them intercept at different altitudes so if one overshoots they pass over/under. But it results in lower capacity per runway than the US system.
- azalemeth 5y ago
  Indeed. Something else I'd like to point out is that it might seem easy to 'blame the Cirrus' pilot or them call out for inattention, but doing so by itself isn't helpful. Aviation is so safe partly because it has managed to turn a culture of blame into a culture of continuous improvement and shared learning: I'd be very surprised if the airport's procedures came out of this unmodified, for example.
  - elliekelly 5y ago
    I’ve probably mentioned this book on HN a hundred times but “Black Box Thinking” discusses the aviation culture of avoiding blame and making sure a problem isn’t repeated and how other industries (like medicine) would benefit hugely from a similar approach. It’s really interesting.
    - EricE 5y ago
      Would also help computer "science" as well :p
    - lbriner 5y ago
      I'm not sure how scalable this is in modern penny-pinching times. In the old days, airlines had to prove they were safe to attract business and this involved accepting that certain practices were harmful and they were therefore improved. Once we got to the 1980s, we had so many airlines trying to survive that corners were cut, recommendations were not followed and various accidents were essentially negligent. Now that lots of smaller airlines have been merged into larger ones, we now have Boeing type problems where the cost of manufacture, safety and development is so much higher than before, no-one wants to put a new plane through the whole approvals process, we just want to re-badge a 737 and get it into service. Similar things happen on the railways in the UK where we have the RAIB to do a similar "no-blame" analysis of a crash/accident yet still time and time again, the same problems surface - lack of preparation, lack of training and lack of following procedures.
      - elliekelly 5y ago
        I agree and it’s somewhat addressed in the book - if you find the premise at all interesting you should definitely read it, even if you’re skeptical of the practicality of implementing the philosophy (for lack of a better word) it’s interesting and the examples are compelling. Some of the examples are whole-cloth cultural changes of entire industries (usually commercial flight actually, IIRC), but some are small, simple, changes that can be implemented by one or two people and still have a dramatic impact. One of the smaller-scale examples from the book that really stuck out was the attitude & approach of a surgeon in an operating room. When surgeons approach mistakes from the perspective of “okay, this happened, let’s focus on how we fix it” mistakes are reported to the surgeon quickly, the surgeon gets accurate information quickly, and can respond appropriately. Result: more mistakes are reported but the surgeon has fewer complications and better outcomes. When surgeons approach mistakes by getting angry or assigning blame to the nurse who did X or the resident who did Y those surgeons have fewer (reported) mistakes but worse outcomes. Why? People don’t fess up because they fear the consequences. And when a mistake is identified, people don’t give accurate and complete information because their primary concern is KYA rather than fixing the problem at hand.
  - phkahler 5y ago
    >> I'd be very surprised if the airport's procedures came out of this unmodified, for example. I'm curious. The airport is at about 5900ft and they were at 6400. If that's AGL for them that seems like a long and high approach. If not, then they were going to do a 3 mile straight in at 500 feet AGL? Either interpretation doesn't fit my (limited, student) experience.
    - azalemeth 5y ago
      KAPA is indeed 5900 MSL, and those heights are also all MSL. Looking at the FAA's charts, https://aeronav.faa.gov/d-tpp/2104/05715R17L.PDF https://aeronav.faa.gov/d-tpp/2104/05715R17L.PDF, this combination of heights and distances isn't totally crazy -- I state without proof (and wait to be corrected!) that the approach is modified because it is a relatively high altitude airport and there may be quite steeply changing terrain underneath. I've never flown there (not even on X-plane) and I'm a low-hours UK person. I haven't done the trig and meterological lookup to work out what their AGL altitude was on that day, but at the very least it's not crazy-wrong from the published chart...
- sokoloff 5y ago
  If the 1 button on autopilot mode is the red autopilot disconnect, “time to hand-fly” button, I agree with you. This turn to final (with the unusual additional warning to “do not fly through final”) is a visual maneuver and I’d expect most every pilot to be hand-flying at that point. (My autopilot and navigator is capable to make that intercept, but it’s way more tedious and distracting to program it than to just fly it.)
  - t0mas88 5y ago
    In the airline world it would at the very least be encouraged and in many cases mandatory to have the underlying approach programmed for this anyway. Even more so if told not to fly through final you would have the localizer up and monitor it. In a Cirrus with what is probably a GFC 700 with flight director capabilities I would expect any competent instrument rated pilot to have the FD on and approach mode armed (the 1 missing button I meant) exactly to avoid this mistake. Great to hand fly, but in a capable airplane just plain stupid not to use all the tools. And even mandatory on the professional side of things in many cases.
    - sokoloff 5y ago
      NB: There is no instrument approach to 17R @ KAPA. I agree I'd have an extended centerline up (it's up by default if I zoom the MFD in close enough in my lesser-equipped A36), but this is a fully visual maneuver. Almost no one is going to define a user waypoint near the touchdown zone for 17R and pull an OBS line off that just so they can use the FD/AP to make an entirely routine turn to final.
      - t0mas88 5y ago
        That makes things a lot harder for the Cirrus pilot. Easy to get the lineup slightly wrong with for example some wind correction in from far away. Crazy that ATC had them do this at the same altitude as conflicting traffic with no underlying approach as a safety net. You can ask someone not to go through final, but that's very easy to miss judge from a couple of miles away.
omegant 5y ago
Looking at the youtube video of the radar with the radio sound that someone posted below, the Cirrus is cleared to runway 17R but he turns to runway 17L. There are 3 possibilities : 1- he mistakes one runway for the other visually, 2- he wrongly thinks he is cleared for the 17L runway 3- or he makes a too wide turn going for the 17R, intruding the 17L area. The cirrus is the one that makes the mistake. The 17 runways are quite close laterally (700’) , it may be either way a bad maneuver (overshooting) or chosing the wrong runway. https://es.flightaware.com/resources/airport/APA/APD/AIRPORT+DIAGRAM/pdf https://es.flightaware.com/resources/airport/APA/APD/AIRPORT... The metro was not expecting another traffic in approach for his runway (I understand that they were in different frequencies with different controllers). During the approach the upper-right side relative angle position in the window of the metro, makes the cirrus hard to spot. I guess he didn’t see the cirrus at all or just barely before the crash. The cirrus is looking at the runway to his right and the other traffic probably the whole time, the metro is in front of him, so he doesn’t see the Metro till he is on top of him. Usually with parallel runways, traffics are kept at different altitudes till they are aligned with their runways. This way if they make a mistake, they are separated by 1000’ vertically with the airplane flying parallel. In this case the cirrus was cleared to visual approach and informed of the cessna he had to follow first. Once he says he has the cessna in sight, he is cleared to visual approach following the cessna. In the same comunication he is informed of the metro flying to the other runway and he replies traffic in sight again. My guess is that he either has the metro in sight at the beginning and then he forgets about it during the maneuver, or he gives traffic in sight two times. Thinking that the second part of the message is for the same aircraft (the cessna) he doesn’t even recognize what the controller is telling him about the metro. This is possible if he is too busy flying the maneuver and not paying proper attention to the radio, he hears “cleared for approach” and “traffic” but he mentally don’t really process the information the controller is giving him. A kind of sensory overload. In airliners we have mandatory TCAS (traffic collision avoidance system) installed that shows you the near traffics in the screen and give you coordinated (between the traffics) automatic avoidance guidance and alarms( one traffic climbs and the other descends or keeps altitude). In busy airports TCAS maneuver happen relatively often (a handfull of times a year) but nowadays is much harder to have a collision or a close call. Also when two pilots are in the cockpit (like airliners) it’s easier that one is concentrated in flying and the other in the communications. It’s very common to correct and be corrected all the time during the flight. It will be interesting to read the official report. Edit: Kudos to the Metro pilot who was super calmed in the radio while declaring emergency and landing the plane. That is really difficult. Edit 2: correcting the airport , KAPA (I talked about KDEN initially which has the same runways but with a bigger separation). This does make a difference regarding the mistake. Thank you Denvercoder9 for the heads up.

t0mas88 5y ago

The Cirrus overshot the centerline of the runway it was supposed to land on. The common way for these situations is for the plane to be on an intercept angle towards the centerline. That's a max 30 degree angle for an instrument approach, but this was a visual approach so it could have been a sharper angle. All it takes to make this mistake in a Cirrus (and other G1000 avionics type small airplanes) is to forget 1 button on the autopilot mode. If it isn't set to capture the final approach track (either GPS or ILS) it will continue straight ahead which in this case means into the side of another airplane. One thing that makes it more likely is that US air traffic control makes heavy use of visual approaches, and then it's allowed to point two aircraft at collision courses on the same altitude because they can see each other. The European way to do this is to have them intercept at different altitudes so if one overshoots they pass over/under. But it results in lower capacity per runway than the US system.

azalemeth 5y ago
Indeed. Something else I'd like to point out is that it might seem easy to 'blame the Cirrus' pilot or them call out for inattention, but doing so by itself isn't helpful. Aviation is so safe partly because it has managed to turn a culture of blame into a culture of continuous improvement and shared learning: I'd be very surprised if the airport's procedures came out of this unmodified, for example.
- elliekelly 5y ago
  I’ve probably mentioned this book on HN a hundred times but “Black Box Thinking” discusses the aviation culture of avoiding blame and making sure a problem isn’t repeated and how other industries (like medicine) would benefit hugely from a similar approach. It’s really interesting.
  - EricE 5y ago
    Would also help computer "science" as well :p
  - lbriner 5y ago
    I'm not sure how scalable this is in modern penny-pinching times. In the old days, airlines had to prove they were safe to attract business and this involved accepting that certain practices were harmful and they were therefore improved. Once we got to the 1980s, we had so many airlines trying to survive that corners were cut, recommendations were not followed and various accidents were essentially negligent. Now that lots of smaller airlines have been merged into larger ones, we now have Boeing type problems where the cost of manufacture, safety and development is so much higher than before, no-one wants to put a new plane through the whole approvals process, we just want to re-badge a 737 and get it into service. Similar things happen on the railways in the UK where we have the RAIB to do a similar "no-blame" analysis of a crash/accident yet still time and time again, the same problems surface - lack of preparation, lack of training and lack of following procedures.
    - elliekelly 5y ago
      I agree and it’s somewhat addressed in the book - if you find the premise at all interesting you should definitely read it, even if you’re skeptical of the practicality of implementing the philosophy (for lack of a better word) it’s interesting and the examples are compelling. Some of the examples are whole-cloth cultural changes of entire industries (usually commercial flight actually, IIRC), but some are small, simple, changes that can be implemented by one or two people and still have a dramatic impact. One of the smaller-scale examples from the book that really stuck out was the attitude & approach of a surgeon in an operating room. When surgeons approach mistakes from the perspective of “okay, this happened, let’s focus on how we fix it” mistakes are reported to the surgeon quickly, the surgeon gets accurate information quickly, and can respond appropriately. Result: more mistakes are reported but the surgeon has fewer complications and better outcomes. When surgeons approach mistakes by getting angry or assigning blame to the nurse who did X or the resident who did Y those surgeons have fewer (reported) mistakes but worse outcomes. Why? People don’t fess up because they fear the consequences. And when a mistake is identified, people don’t give accurate and complete information because their primary concern is KYA rather than fixing the problem at hand.
- phkahler 5y ago
  >> I'd be very surprised if the airport's procedures came out of this unmodified, for example. I'm curious. The airport is at about 5900ft and they were at 6400. If that's AGL for them that seems like a long and high approach. If not, then they were going to do a 3 mile straight in at 500 feet AGL? Either interpretation doesn't fit my (limited, student) experience.
  - azalemeth 5y ago
    KAPA is indeed 5900 MSL, and those heights are also all MSL. Looking at the FAA's charts, https://aeronav.faa.gov/d-tpp/2104/05715R17L.PDF https://aeronav.faa.gov/d-tpp/2104/05715R17L.PDF, this combination of heights and distances isn't totally crazy -- I state without proof (and wait to be corrected!) that the approach is modified because it is a relatively high altitude airport and there may be quite steeply changing terrain underneath. I've never flown there (not even on X-plane) and I'm a low-hours UK person. I haven't done the trig and meterological lookup to work out what their AGL altitude was on that day, but at the very least it's not crazy-wrong from the published chart...
sokoloff 5y ago
If the 1 button on autopilot mode is the red autopilot disconnect, “time to hand-fly” button, I agree with you. This turn to final (with the unusual additional warning to “do not fly through final”) is a visual maneuver and I’d expect most every pilot to be hand-flying at that point. (My autopilot and navigator is capable to make that intercept, but it’s way more tedious and distracting to program it than to just fly it.)
- t0mas88 5y ago
  In the airline world it would at the very least be encouraged and in many cases mandatory to have the underlying approach programmed for this anyway. Even more so if told not to fly through final you would have the localizer up and monitor it. In a Cirrus with what is probably a GFC 700 with flight director capabilities I would expect any competent instrument rated pilot to have the FD on and approach mode armed (the 1 missing button I meant) exactly to avoid this mistake. Great to hand fly, but in a capable airplane just plain stupid not to use all the tools. And even mandatory on the professional side of things in many cases.
  - sokoloff 5y ago
    NB: There is no instrument approach to 17R @ KAPA. I agree I'd have an extended centerline up (it's up by default if I zoom the MFD in close enough in my lesser-equipped A36), but this is a fully visual maneuver. Almost no one is going to define a user waypoint near the touchdown zone for 17R and pull an OBS line off that just so they can use the FD/AP to make an entirely routine turn to final.
    - t0mas88 5y ago
      That makes things a lot harder for the Cirrus pilot. Easy to get the lineup slightly wrong with for example some wind correction in from far away. Crazy that ATC had them do this at the same altitude as conflicting traffic with no underlying approach as a safety net. You can ask someone not to go through final, but that's very easy to miss judge from a couple of miles away.

omegant 5y ago

Looking at the youtube video of the radar with the radio sound that someone posted below, the Cirrus is cleared to runway 17R but he turns to runway 17L. There are 3 possibilities : 1- he mistakes one runway for the other visually, 2- he wrongly thinks he is cleared for the 17L runway 3- or he makes a too wide turn going for the 17R, intruding the 17L area. The cirrus is the one that makes the mistake. The 17 runways are quite close laterally (700’) , it may be either way a bad maneuver (overshooting) or chosing the wrong runway. https://es.flightaware.com/resources/airport/APA/APD/AIRPORT+DIAGRAM/pdf https://es.flightaware.com/resources/airport/APA/APD/AIRPORT... The metro was not expecting another traffic in approach for his runway (I understand that they were in different frequencies with different controllers). During the approach the upper-right side relative angle position in the window of the metro, makes the cirrus hard to spot. I guess he didn’t see the cirrus at all or just barely before the crash. The cirrus is looking at the runway to his right and the other traffic probably the whole time, the metro is in front of him, so he doesn’t see the Metro till he is on top of him. Usually with parallel runways, traffics are kept at different altitudes till they are aligned with their runways. This way if they make a mistake, they are separated by 1000’ vertically with the airplane flying parallel. In this case the cirrus was cleared to visual approach and informed of the cessna he had to follow first. Once he says he has the cessna in sight, he is cleared to visual approach following the cessna. In the same comunication he is informed of the metro flying to the other runway and he replies traffic in sight again. My guess is that he either has the metro in sight at the beginning and then he forgets about it during the maneuver, or he gives traffic in sight two times. Thinking that the second part of the message is for the same aircraft (the cessna) he doesn’t even recognize what the controller is telling him about the metro. This is possible if he is too busy flying the maneuver and not paying proper attention to the radio, he hears “cleared for approach” and “traffic” but he mentally don’t really process the information the controller is giving him. A kind of sensory overload. In airliners we have mandatory TCAS (traffic collision avoidance system) installed that shows you the near traffics in the screen and give you coordinated (between the traffics) automatic avoidance guidance and alarms( one traffic climbs and the other descends or keeps altitude). In busy airports TCAS maneuver happen relatively often (a handfull of times a year) but nowadays is much harder to have a collision or a close call. Also when two pilots are in the cockpit (like airliners) it’s easier that one is concentrated in flying and the other in the communications. It’s very common to correct and be corrected all the time during the flight. It will be interesting to read the official report. Edit: Kudos to the Metro pilot who was super calmed in the radio while declaring emergency and landing the plane. That is really difficult. Edit 2: correcting the airport , KAPA (I talked about KDEN initially which has the same runways but with a bigger separation). This does make a difference regarding the mistake. Thank you Denvercoder9 for the heads up.