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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

#131

Post by addicted »

NikolaNovak wrote: post #100
iforgotpassword wrote: post #60

Earlier quoted context omitted.

Well this shit doesn't sound any better: 1565207 At cruise flight, our Wi-Fi stopped working. I then saw that I was unable to access the Pilot Mobile app. Since I do not routinely copy the flight plan to iBook or acrobat (we are not required to do this), I was unable to access the flight plan. I've lost Wi-Fi before but not had this problem. Maybe it's a 737max thing. My First Officer had a copy on iBook and airdropp…

Boggles the mind on several levels: 1. That airlines would use consumer tablets without hard-copy backup as matter of procedure. I remember Air Canada announcing it and how it would save so much weight for both pilots and the airplane, and thinking... I print my Google Maps as a backup for roadtrips, I sure as heck would do it on a flight! 2. Perhaps I'm misjudging, but the tone and perspective of pilot makes me worr…

As a non technical person, who is about to fly an 80 ton vehicle for extended distances, local backups of WiFi dependent data is not likely to be a major concern.

Especially if (a) it’s not part of your extensive checklists, which would reasonably be expected to be included if it was important, and (b) you’ve lost WiFi in other planes before without losing your flight plan.

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

#132

Post by kenneth »

This is a great video that does a concise and understandable of the main theory for the issue that occured on the LionAir flight: https://www.youtube.com/watch?v=zfQW0upkVus

It was very helpful for me to understand exactly what "runaway trim" meant. Essentially, it's a force (down or up) on the elevator on the horizontal stabilizer. The pilot still controls it from his yoke, but the more trim applied the more it pushes the result in a given direction. If the system applies trim consistently to push the nose down (to avoid what it thinks is an imminent staff), it will progressively more difficult for the pilot to counteract that and pitch up. Eventually, it's too much to handle.

This situation should be easily detectable, from what I understand, due to large wheels moving visibly in the center console, and the pilots can counteract the trim in a known procedure.

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

#133

Post by siwatanejo »

lsh123 wrote: post #101
sfilargi wrote: post #99

For a car analogy, imagine Tesla creates a new model that under certain conditions tends to over-steer left. To prevent any accidents because of that, they have added a system that turns the steering wheel clockwise. To disable the system it is not enough to try to prevent by force the steering wheel from turning, but you have to press a button that disables electric steering assistance. Notice they have never briefe…

Incorrect analogy. Runaway trim is a common and known problem with a solution to pull the electric trim breaker. MCAS failure is very similar in appearance and have exactly the same solution.

Can you think of a better car analogy? I'm genuinely curious.

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

#134

Post by sn41 »

dpwm wrote: post #91
ehsankia wrote: post #64

Earlier quoted context omitted.

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.

1555013 is pretty damning in telling how the airlines treated the MAX as the same type as the 737-800: "I had my first flight on the Max [to] ZZZ1. We found out we were scheduled to fly the aircraft on the way to the airport in the limo. We had a little time [to] review the essentials in the car. Otherwise we would have walked onto the plane cold.My post flight evaluation is that we lacked the knowledge to operate th…

This is I think what is very very close to the truth. Some pilots are trained on the MAX, but later, untrained pilots are arbitrarily assigned to these planes. I am not sure that even emails help - with the amount of newsletters, and ad mails we receive, this email might be missed, or even when read, its importance might be missed.

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

#136

Post by lsh123 »

siwatanejo wrote: post #133
lsh123 wrote: post #101

Earlier quoted context omitted.

Incorrect analogy. Runaway trim is a common and known problem with a solution to pull the electric trim breaker. MCAS failure is very similar in appearance and have exactly the same solution.

Can you think of a better car analogy? I'm genuinely curious.

You know that you need to break when you get close to another veichle in front. Now you have a new shiny cruise control (without latest distance keeping feature). Well, you still need to break when you get close to a veichle in front of you.

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

#137

Post by xnomad »

jashkenas wrote: post #53
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…

Great links! Here are the three 737-related ASRS reports that mention MCAS: ACN: 1597286 "Day 3 of 3 departing in a MAX 8 after a long overnight. I was well rested and had discussed the recent MAX 8 MCAS guidance with the Captain. On departure, we had strong crosswinds (gusts > 30 knots) directly off the right wing, however, no LLWS or Micro-burst activity was reported at the field. After verifying LNAV, selecting ge…

The first and second report look to be the FO's and Captain's for the same incident. And don't make sense as I though MCAS is during manual flight. Why would Auto Pilot need MCAS, it's like Auto Pilot using Auto Pilot?

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

#138

Post by [deleted] »

ordinaryradical wrote: post #72
jashkenas wrote: post #53

Earlier quoted context omitted.

Great links! Here are the three 737-related ASRS reports that mention MCAS: ACN: 1597286 "Day 3 of 3 departing in a MAX 8 after a long overnight. I was well rested and had discussed the recent MAX 8 MCAS guidance with the Captain. On departure, we had strong crosswinds (gusts > 30 knots) directly off the right wing, however, no LLWS or Micro-burst activity was reported at the field. After verifying LNAV, selecting ge…

These all sound extremely serious and damning, but it's hard to know whether these match the typical tone and content of these kind of reports. Is this is well inside the standard for adjusting to a new aircraft or does this suggest a serious hazard left unaddressed?

[deleted]

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

#139

Post by xnomad »

celticninja wrote: post #122
pdonis wrote: post #102

Earlier quoted context omitted.

What I'm gathering from these reports is not encouraging: (1) The third report says that MCAS only operates in manual flight. The second report appears to confirm that since the pilot says he engaged autopilot sooner than usual to remove the possible MCAS threat. (2) However, both the first and second reports describe uncommanded pitch down events while in autopilot . That means there is another problem in addition t…

Which Airbus model is affected?

Probably referring to A330: https://en.wikipedia.org/wiki/Qantas_Flight_72 They never quite figured out the root cause of the un-commanded dives

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

#140

Post by ggm »

dajohnson89 wrote: post #121
dpwm wrote: post #45

Earlier quoted context omitted.

regex? I just grepped "B737 max" and found 11 entries. "737.{0,20}max" (case insensitive) yields 20. [0] [0] CSV output: https://pastebin.com/87N023cx

So 20 MAX-related issues out of ~850. How is that significant?

We'd need some meta analysis of the rate of issues for other plane types by release date to track the declining exponential curve of bugs to legacy.

"all new systems have bugs. this may not be unusual"

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