4 ms·

Is this the five independent bit flips in worst possible order and combination from cosmic rays failure? First -> if this is your worst failure mode (ie, worse

Is this the five independent bit flips in worst possible order and combination from cosmic rays failure? First -> if this is your worst failure mode (ie, worse than pilot error, mechanical fatigue and failure, engine failures, fueling issues, crazy passengers etc) then you have a plane and overall safety system that is incredible. Second -> this wild set of events again does not crash the plane - though it would put the pilots in a bad spot similar to the existing MCAS issues.

salawat 7y ago
>First -> if this is your worst failure mode (ie, worse than pilot error, mechanical fatigue and failure, engine failures, fueling issues, crazy passengers etc) then you have a plane and overall safety system that is incredible. Or would be, if it didn't violate design constraints that demand no single point of failure can have the capability to result in loss of the aircraft. I.e. components with failure profiles of catastrophic severity MUST have redundancy. You test the least likely events to ensure you have sufficient fault tolerance for that very reason. >Second -> this wild set of events again does not crash the plane - though it would put the pilots in a bad spot similar to the existing MCAS issues. Actually, one of the three test pilots did in fact lose the plane in the simulator. Hence the reclassification of the flight computer as a component with a catastrophic failure potential. Look, I'm about the last person you're going to get to buy into the awesome safety of an aircraft that can't even pass a textbook test case for computing in adverse environments. If the bloody thing was so safe and high quality, it wouldn't have been able to suffer that induced failure in the first place. It would have been designed out. The fact Boeing was caught off guard by that failure means they weren't looking very hard, and were banking that no one else would either. Which is generally a really bad assumption to make, because Murphy finds a way. Every time.
- privateSFacct 7y ago
  There's lots of potential for failure that the planes allow when flying. Some quick examples - they could have sensors around gas quality but do not - they rely on the folks providing the avgas to have good fuel. They could do built in weight and balance calcs with sensors - they do not, they rely on poor estimates for that. etc. Boeing in particular ALLOWS pilots to fly planes outside of most flight envelope limits. They do this in part because historically they didn't trust the computer as much and trusted pilots more. Airbus by contrast doesn't let you do this unless you take air data totally offline or something crazy to force alternative law. I suspect boeing will be moving towards the airbus model which is probably right. Airbus had arguably less local myopia when designing their planes - ie, future pilot populations come from a big group and making the plane as error proof as possible is best. Airbus had some issues around their automation without pilot override initially but I think those are resolved by now. If you want a scary video - check out this early A320 flying - first fly by wire / autothrottle: https://www.youtube.com/watch?v=YAg-WauGrLU https://www.youtube.com/watch?v=YAg-WauGrLU Can't have been a good feeling as that pilot. Note that the A320 is now considered a very safe plane. Aircraft have evolved from systems with almost no built in redundancy or safety. The design of the 737 is pretty old - 1967 or so. Let that sink in for a bit, consider what type of tech they had back in. This is not a 777 generation plane or even A320.

salawat 7y ago

>First -> if this is your worst failure mode (ie, worse than pilot error, mechanical fatigue and failure, engine failures, fueling issues, crazy passengers etc) then you have a plane and overall safety system that is incredible. Or would be, if it didn't violate design constraints that demand no single point of failure can have the capability to result in loss of the aircraft. I.e. components with failure profiles of catastrophic severity MUST have redundancy. You test the least likely events to ensure you have sufficient fault tolerance for that very reason. >Second -> this wild set of events again does not crash the plane - though it would put the pilots in a bad spot similar to the existing MCAS issues. Actually, one of the three test pilots did in fact lose the plane in the simulator. Hence the reclassification of the flight computer as a component with a catastrophic failure potential. Look, I'm about the last person you're going to get to buy into the awesome safety of an aircraft that can't even pass a textbook test case for computing in adverse environments. If the bloody thing was so safe and high quality, it wouldn't have been able to suffer that induced failure in the first place. It would have been designed out. The fact Boeing was caught off guard by that failure means they weren't looking very hard, and were banking that no one else would either. Which is generally a really bad assumption to make, because Murphy finds a way. Every time.

privateSFacct 7y ago
There's lots of potential for failure that the planes allow when flying. Some quick examples - they could have sensors around gas quality but do not - they rely on the folks providing the avgas to have good fuel. They could do built in weight and balance calcs with sensors - they do not, they rely on poor estimates for that. etc. Boeing in particular ALLOWS pilots to fly planes outside of most flight envelope limits. They do this in part because historically they didn't trust the computer as much and trusted pilots more. Airbus by contrast doesn't let you do this unless you take air data totally offline or something crazy to force alternative law. I suspect boeing will be moving towards the airbus model which is probably right. Airbus had arguably less local myopia when designing their planes - ie, future pilot populations come from a big group and making the plane as error proof as possible is best. Airbus had some issues around their automation without pilot override initially but I think those are resolved by now. If you want a scary video - check out this early A320 flying - first fly by wire / autothrottle: https://www.youtube.com/watch?v=YAg-WauGrLU https://www.youtube.com/watch?v=YAg-WauGrLU Can't have been a good feeling as that pilot. Note that the A320 is now considered a very safe plane. Aircraft have evolved from systems with almost no built in redundancy or safety. The design of the 737 is pretty old - 1967 or so. Let that sink in for a bit, consider what type of tech they had back in. This is not a 777 generation plane or even A320.