3 ms·

A similar thing happened with the captain of SAS MD-81 in 1993[1]. Clear ice had formed on the upper side of wings overnight, but it was not detected during de-

by mopsi 7y ago

A similar thing happened with the captain of SAS MD-81 in 1993[1]. Clear ice had formed on the upper side of wings overnight, but it was not detected during de-icing. Shortly after takeoff, pieces of ice broke off and hit engines, deforming fan blades, which disturbed airflow and caused right engine to surge 25 seconds into the flight. Pilots properly responded with thrust reduction to decrease engine stress, but unknown to them, the MD-81 had been fitted with Automatic Thrust Restoration[2] that kept increasing thrust to maintain normal climb setting. Increased thrust led to surging of the left engine too, until both engines failed at 78 seconds. The aircraft crashed into a field and broke into three parts (everyone survived).[3] Post-crash analysis determined that reduced thrust would have kept both engines operational, and maintained thrust would've lead to failure of only the right engine, which would have allowed to keep flying and perform a safe landing. ATR increased thrust and caused both engines to fail. Captain of the flight retired from flying, saying that he lost trust in airplanes. [1] https://en.wikipedia.org/wiki/Scandinavian_Airlines_Flight_751 https://en.wikipedia.org/wiki/Scandinavian_Airlines_Flight_7... [2] https://patents.justia.com/patent/4662171 https://patents.justia.com/patent/4662171 [3] https://i.imgur.com/k4q0WMm.png https://i.imgur.com/k4q0WMm.png and https://i.imgur.com/KzPNhsU.jpg https://i.imgur.com/KzPNhsU.jpg

IfOnlyYouKnew 7y ago
For every vindicated hero, there are probably dozens of pilots who would no longer be alive without smarter systems. Airline fatalities decreased 10-fold in the last 30 years, while total miles travelled increased by the same factor. Flying today is 100x safer now, and I don't quite understand peoples' fetish with human control.
- whyenot 7y ago
  Where do those figures come from? They appear to be completely inaccurate. Looking here [1], while there has certainly been a reduction in fatalities over the past 30 years, it's not even close to 10x. Maybe 2x or 4x. As far as miles travelled, there has been at best a 2x increase over the past 30 years, at least for the US[2]. Airline travel certainly has become safer, at least on a per-mile basis, but 100x safer? That's fantasy. 1. https://en.wikipedia.org/wiki/Aviation_accidents_and_incidents#Statistics https://en.wikipedia.org/wiki/Aviation_accidents_and_inciden... 2. https://www.bts.gov/content/us-passenger-miles https://www.bts.gov/content/us-passenger-miles
  - IfOnlyYouKnew 7y ago
    Sorry, I continue calculating from 2000 because it's easier, but the errors bars of that are starting to grow. Make it 50 years: https://en.wikipedia.org/wiki/Aviation_safety#/media/File:1970-2018_fatalities_per_revenue_passenger_kilometre_in_air_transport_(cropped).png https://en.wikipedia.org/wiki/Aviation_safety#/media/File:19... In any case, the larger point should be undeniably clear. Air travel is getting safer and safer.
    - jplayer01 7y ago
      You've only established that flying is getting safer. None of this proves or even implies that most of that improvement in safety is because of added features like ATR, especially ones that subtly subvert expectations and remove agency/control from pilots.
      - nick_kline 7y ago
        We need standards for ways to recognize when the computer controls have chosen to override the pilot, why they are doing it, and a way for the human to override. This is hard, not easy, because there are so many things going. One place to look and report back. Tesla has some of these things. It beeps at you when it detects you are about to hit cars in front of you. If you are in traffic and it doesn't see that your lane will be going around say a stopped car in a different lane in traffic you can easily override it. Similarly for the driver can override the autopilot, and because it has a kind of tactile feeling when you use the steering wheel to override the self-driving. Still it's far far from perfect, current evidence being the front end crashes into immobile barriers. But they have these notions built in of feedback, control, override. I expect every self-driving vehicle has something different in how they handle these things. Eventually we'll have standards across car lines. I bet planes are all different with all those amazingly huge number of controls the pilot has to understand.
    - FabHK 7y ago
      > since 1970 [to 2018] fatalities per trillion revenue passenger kilometre (RPK) decreased 54 fold from 3,218 to 59.
- swiley 7y ago
  That's exactly the opposite of the reaction I had which was "ugh, another example of software the human operators aren't told about doing something stupid because the author thought they understood every situation better than the people actually in the situation." Furthermore, you don't know that it's software that's improving the safety of flights, it could be changes in procedures and training.

by mopsi 7y ago

IfOnlyYouKnew 7y ago

For every vindicated hero, there are probably dozens of pilots who would no longer be alive without smarter systems. Airline fatalities decreased 10-fold in the last 30 years, while total miles travelled increased by the same factor. Flying today is 100x safer now, and I don't quite understand peoples' fetish with human control.

whyenot 7y ago
Where do those figures come from? They appear to be completely inaccurate. Looking here [1], while there has certainly been a reduction in fatalities over the past 30 years, it's not even close to 10x. Maybe 2x or 4x. As far as miles travelled, there has been at best a 2x increase over the past 30 years, at least for the US[2]. Airline travel certainly has become safer, at least on a per-mile basis, but 100x safer? That's fantasy. 1. https://en.wikipedia.org/wiki/Aviation_accidents_and_incidents#Statistics https://en.wikipedia.org/wiki/Aviation_accidents_and_inciden... 2. https://www.bts.gov/content/us-passenger-miles https://www.bts.gov/content/us-passenger-miles
- IfOnlyYouKnew 7y ago
  Sorry, I continue calculating from 2000 because it's easier, but the errors bars of that are starting to grow. Make it 50 years: https://en.wikipedia.org/wiki/Aviation_safety#/media/File:1970-2018_fatalities_per_revenue_passenger_kilometre_in_air_transport_(cropped).png https://en.wikipedia.org/wiki/Aviation_safety#/media/File:19... In any case, the larger point should be undeniably clear. Air travel is getting safer and safer.
  - jplayer01 7y ago
    You've only established that flying is getting safer. None of this proves or even implies that most of that improvement in safety is because of added features like ATR, especially ones that subtly subvert expectations and remove agency/control from pilots.
    - nick_kline 7y ago
      We need standards for ways to recognize when the computer controls have chosen to override the pilot, why they are doing it, and a way for the human to override. This is hard, not easy, because there are so many things going. One place to look and report back. Tesla has some of these things. It beeps at you when it detects you are about to hit cars in front of you. If you are in traffic and it doesn't see that your lane will be going around say a stopped car in a different lane in traffic you can easily override it. Similarly for the driver can override the autopilot, and because it has a kind of tactile feeling when you use the steering wheel to override the self-driving. Still it's far far from perfect, current evidence being the front end crashes into immobile barriers. But they have these notions built in of feedback, control, override. I expect every self-driving vehicle has something different in how they handle these things. Eventually we'll have standards across car lines. I bet planes are all different with all those amazingly huge number of controls the pilot has to understand.
  - FabHK 7y ago
    > since 1970 [to 2018] fatalities per trillion revenue passenger kilometre (RPK) decreased 54 fold from 3,218 to 59.
swiley 7y ago
That's exactly the opposite of the reaction I had which was "ugh, another example of software the human operators aren't told about doing something stupid because the author thought they understood every situation better than the people actually in the situation." Furthermore, you don't know that it's software that's improving the safety of flights, it could be changes in procedures and training.