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Boeing 737 Max pilots complained to feds for months about suspected safety flaw

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Re: Boeing 737 Max pilots complained to feds for months about suspected safety flaw

#61

Post by mannykannot »

tuna-piano wrote: post #30

Some context: 1. There have been 865 737 related ASRS reports since 1/1/2018 2. I don't know how to quickly separate out 737-MAX reports from the non 737-MAX reports, as the ASRS database doesn't include 737-MAX as an airplane type! From scanning, I can say that there are more than five MAX related reports, though. [1] All 865 737 reports since 1/1/2018 CSV - http://s000.tinyupload.com/index.php?file_id=5466867979406…

Thanks for the documents! I searched through item 1 for 'trim', and while I found some trim failure reports, and the complaint about Boeing's nondisclosure of MCAS in its documentation, I did not notice any concerns over disabling a runaway trim situation.

Re: Boeing 737 Max pilots complained to feds for months about suspected safety flaw

#62

Post by ergocoder »

This is off topic. But I've been skeptical of the commercial aviation accident risk compared to cars.

I'm not saying cars are safer. But using accident count per mileage seems a bit odd, especially when the most risky parts of flying are taking off and landing.

A plane travelling 400 more miles doesn't incur much more risk. But a car travelling 400 more miles incur a much bigger risk (e.g. fatigue, car malfunctioning). So, of course, the stats for planes is going to look much better.

I wonder if anyone has an insight into why we are using this metrics, and what is a better metrics?

Re: Boeing 737 Max pilots complained to feds for months about suspected safety flaw

#63

Post by jahewson »

mannykannot wrote: post #32

There are at least three inter-related issues here: 1) Was MCAS an issue in the Ethiopian Airlines crash? 2) Did Boeing err, prior to the Lion Air crash, in not informing pilots of the existence of MCAS, and the way it changes how a failure is experienced by the flight crew? 3) Does MCAS pose a risk that cannot be adequately addressed through appropriate awareness and training? IIRC, after the existence of MCAS was d…

> 3) Does MCAS pose a risk that cannot be adequately addressed through appropriate awareness and training?

If it fails this frequently, yes. Obviously pilots need to be informed about the failure modes of the planes they fly - but they also need to not be constantly subjected to them. Modern commercial aircraft are supposed to be waaay more reliable than this.

Re: Boeing 737 Max pilots complained to feds for months about suspected safety flaw

#64

Post by ehsankia »

tuna-piano wrote: post #30

Some context: 1. There have been 865 737 related ASRS reports since 1/1/2018 2. I don't know how to quickly separate out 737-MAX reports from the non 737-MAX reports, as the ASRS database doesn't include 737-MAX as an airplane type! From scanning, I can say that there are more than five MAX related reports, though. [1] All 865 737 reports since 1/1/2018 CSV - http://s000.tinyupload.com/index.php?file_id=5466867979406…

It would be ironic if the lack of 737-MAX category for reports is why these reports never made it to the people who needed to see them, which caused the issue to go unnoticed.

Re: Boeing 737 Max pilots complained to feds for months about suspected safety flaw

#65

Post by reneherse »

ergocoder wrote: post #62

This is off topic. But I've been skeptical of the commercial aviation accident risk compared to cars. I'm not saying cars are safer. But using accident count per mileage seems a bit odd, especially when the most risky parts of flying are taking off and landing. A plane travelling 400 more miles doesn't incur much more risk. But a car travelling 400 more miles incur a much bigger risk (e.g. fatigue, car malfunctioning…

Perhaps a better metric would be accidents per unit of time.

Re: Boeing 737 Max pilots complained to feds for months about suspected safety flaw

#66

Post by Udik »

ergocoder wrote: post #62

This is off topic. But I've been skeptical of the commercial aviation accident risk compared to cars. I'm not saying cars are safer. But using accident count per mileage seems a bit odd, especially when the most risky parts of flying are taking off and landing. A plane travelling 400 more miles doesn't incur much more risk. But a car travelling 400 more miles incur a much bigger risk (e.g. fatigue, car malfunctioning…

I'd say it's accidents per person/hour. And I've read somewhere that the figures used to be similar for cars and airplanes (though aircraft safety is constantly improving, cars probably less).

Re: Boeing 737 Max pilots complained to feds for months about suspected safety flaw

#67

Post by paxys »

ergocoder wrote: post #62

This is off topic. But I've been skeptical of the commercial aviation accident risk compared to cars. I'm not saying cars are safer. But using accident count per mileage seems a bit odd, especially when the most risky parts of flying are taking off and landing. A plane travelling 400 more miles doesn't incur much more risk. But a car travelling 400 more miles incur a much bigger risk (e.g. fatigue, car malfunctioning…

We use it because there is really no good metric to compare the two.

Re: Boeing 737 Max pilots complained to feds for months about suspected safety flaw

#68

Post by [deleted] »

mannykannot wrote: post #32

There are at least three inter-related issues here: 1) Was MCAS an issue in the Ethiopian Airlines crash? 2) Did Boeing err, prior to the Lion Air crash, in not informing pilots of the existence of MCAS, and the way it changes how a failure is experienced by the flight crew? 3) Does MCAS pose a risk that cannot be adequately addressed through appropriate awareness and training? IIRC, after the existence of MCAS was d…

[deleted]

Re: Boeing 737 Max pilots complained to feds for months about suspected safety flaw

#69

Post by mannykannot »

jahewson wrote: post #63
mannykannot wrote: post #32

There are at least three inter-related issues here: 1) Was MCAS an issue in the Ethiopian Airlines crash? 2) Did Boeing err, prior to the Lion Air crash, in not informing pilots of the existence of MCAS, and the way it changes how a failure is experienced by the flight crew? 3) Does MCAS pose a risk that cannot be adequately addressed through appropriate awareness and training? IIRC, after the existence of MCAS was d…

> 3) Does MCAS pose a risk that cannot be adequately addressed through appropriate awareness and training? If it fails this frequently, yes. Obviously pilots need to be informed about the failure modes of the planes they fly - but they also need to not be constantly subjected to them. Modern commercial aircraft are supposed to be waaay more reliable than this.

How frequently it fails seems to depend on the answer to question 1 - unless you are aware of other incidents beyond the Lion Air crash?

Re: Boeing 737 Max pilots complained to feds for months about suspected safety flaw

#70

Post by CamperBob2 »

mrpippy wrote: post #37
alfalfasprout wrote: post #29

Earlier quoted context omitted.

They mostly seem to agree with each other which is the scary part. Several of them reference a completely unexplained pitch up/down behavior during a climb. During landing an unplanned nosedive would be disastrous.

MCAS can only activate when flaps are raised, it shouldn't cause any unexpected trim changes during landing. This is why the Lion Air flight had a normal takeoff/climb until they raised the flaps.

Aren't the flaps up during landing?
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