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.
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 briefed you about this new system because they didn't want to retrain you.
You happily drive along the highway at 70mph when the system malfunctions and incorrectly thinks the car is over-steering left, so the steering wheel starts rotating clockwise. The car swiftly moves to the lane in your right as you use all your strength to prevent it and manage to bring the car back in the lane.
In the mean time all kind of lights and sounds go off on your cockpit. In 5 seconds, while you are trying to find out what to make out of all the lights flashing, the steering wheel starts turning the card right again. This time you are not so lucky and you crash into the truck on your right.
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.
That analogy doesn't really hold. My understanding is that these angle correction issues are due to the oversized engines for the 737 fuselage. The correction system is there as a solution to that which doesn't involve scrapping the line and staying with larger plane sizes .
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?
The relevance of the metric depends on what you're using it for. If you decide whether to drive or fly to a destination based on how safe it is, risk/distance is a perfectly reasonable metric. Since flying is a means of transportation, it seems reasonable to judge the risk relative to the amount of transportation you get out of it.
That doesn't discount the fact that most of the risk is in take-off/landing, so if you use fleet-average statistics you'll bias the risk of short flights low and long flight high. Air safety studies do also use additional metrics like accidents/hour and accidents/segment, but those are mostly useful for comparing between different types of aviation.
Ignoring the silly ones (Space Shuttle, Skidiving and Paragliding), we see that Motorcycles are by far the most dangerous mode of transport, across all metrics. Buses do very well, only losing out to Aircraft on distance.
When you look at Aircraft by number of journeys, the risk is significantly higher - nearly 3 times higher than car journeys!
That said, there are othe factors to consider here: these metrics only track _deaths_. So non-fatal incidents (of which the majority involving cars are) aren't considered.
The same sort of problem occurs on the other end when you try to compare the risk of driving vs walking. Cars are 5 times faster in the city and 20 times faster on the highway than walking. The trips are almost always shorter on foot, you drive to the far away big box store but would walk to the neighbourhood store. Better metrics than risk per unit of distance would be risk per unit of time spent or risk per trip.
I would point out that in a similar way few people drive between continents but flight is common.
It's a useful metric because, when comparing auto and plane safety, consumers are usually deciding between taking a plane and a car for the same distance. We could give them risk as a function of distance by taking the increased takeoff/landing risk into account, but generally people only compare the two for fairly long trips.
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).
Not to mention you have a fairly good chance of surviving a car accident whereas a plane falling out of the sky is almost ways bad news for passengers.
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 disclosed, the US pilots' unions were divided over this issue, with the union representing Southwest pilots castigating Boeing for its nondisclosure, while that representing United pilots did not consider it to be a big issue. Unfortunately, this article does not make it clear where pilots stand on issue 3, and the investigation of the Ethiopian Airlines crash might reveal additional issues.
The forthcoming software upgrade for MCAS certainly implies that there were improvements to be made.
Another issue is that the engines on the Max version are larger than the NG version and didn’t fit under the wing. So they had to raise the mounting point forward and up as well as extend the nose gear 18 inches. These changes caused the plane to have a different flight profile to the NG version. However it would have been disasterous if pilots already certified for the 737 couldn’t fly the 737 max. So boeing implemented the MCAS so make the max handle like the NG. That move is drawing a lot of skepticism because if the computer screws up then the pilots were never really trained to fly the Max
> The forthcoming software upgrade for MCAS certainly implies that there were improvements to be made.
Not according to Boeing... "Boeing has been developing a flight control software enhancement for the 737 MAX, designed to make an already safe aircraft even safer."[1]
To me an incredibly infuriating statement. The 737-MAX has a fatal crash rate of ~4 per million, when compared to .1 per million for the 737-NG models (40x). There is no currently flying major commercial aircraft which has a higher fatal crash rate than the 737-MAX [2] [3] Of course the MAX has a small sample size, but that's still not evidence of safety.
What data is Boeing looking at to show that their aircraft is considered a safe aircraft?
> 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.
I don't know the answer to 1 or 2, but regarding 3, if the issue in the reports via this article are the same issue, which it seems like they may be, then no I don't believe it poses a risk that can't be addressed through training. Through awareness these pilots and FOs filing reports seemed to know, at least through intuition if not outright knowledge of the new MCAS system, to disconnect the autopilot system when the nose goes down inappropriately.
My question is, should the onus be on the pilots? Yes, they should know about it if they're going to be piloting an aircraft with it, but is this expected behavior? To me it seems more like a bug than expected behavior...why would you want to pitch downwards in a climb?
I don't really understand defense of Boeing in any scenario. This seems like a mistake in any case, whether it's just lack of instruction or documentation in the relevant flight manuals, or an outright system failure.
The thing that worries me most is that, based on mere amateur observations in the media, the number of incidents involving user interfaces, repeated changes to procedures, and software fixes to "unexpected" corner-cases seems to have been in the increase.
To the uninitiated, it seems that problems in airline incidents used to revolve around mechanical failures, bad wiring, sensor malfunctions, toasted electronics causing smell of smoke and such. Plain and simple. Issue a fix in the design and apply to all planes of the same type, and you'll end up reducing the failure surface bit by bit.
I might be totally wrong about this because I don't track actual data. But if I've spotted the trend right it's scary because the problems are shifting into our space, i.e. software engineering. And being a software engineer, I know we're pretty much fucked at that point. We've only ever managed to write reliable and trustworthy software when we've split it into very tiny pieces that we can verify and kept the number of pieces small.
Maybe aviation computers used to be much simpler that they could be verified more throughoutly. Maybe airplanes used to have less features and they could keep the complexity sufficiently down and functionality orthogonal. Maybe there was enough human glue in between the systems so that there was a live sanity-check during flights and pilots could react properly if the computers didn't agree on something.
But now I sense a new category of error conditions that are eerily similar to what we've had in non-critical software for decades where assumptions are laid on top of other assumptions, and when they fail the whole stack comes crashing down. Only this time there might be a whole plane coming down instead of getting a curious SIGSEGV on the screen with a blinking cursor. It might start as an innocent "couldn't access flight plan because of wifi went down" but such interdependencies between certified and uncertified systems grow exponentially and this will snowball into the unmanageable very soon.
> The News found at least five complaints about the Boeing model in a federal database where pilots can voluntarily report about aviation incidents without fear of repercussions.
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.
There have been 865 total 737 reports in the ASRS database since 1/1/2018 (linked the results of my search in another comment in this thread). There doesn't appear to be a 737-MAX filter (groups all 737-800s and 737-900s together it seems), so it's tough to say.
In addition, it seems like some pilots were motivated to submit reports on their MAX experiences due to the Lion Air incident.
I'm appalled at Boeing's response, and I agree with the Europeans, other countries, and Senator Cruz and others that the planes should probably be grounded, at least very briefly.
But the news reporting that an unknown-relative-to-other-planes percentage of complaints were filed by pilots, especially when those reports could theoretically be merely annoyed pilots responding to a perceived lack of training, or piling on after Lion Air, doesn't tell me a whole lot I didn't already know.
Please make a conscious choice when flying 737 Max on US domestic flights. It is your right to know the type of aircraft when you are booking your flight. Switching to a reasonably expensive alternative is worth more than any foreseeable trouble.
> It is your right to know the type of aircraft when you are booking your flight.
This is not actually any kind of right in the US. The airline can switch to using a MAX just before the flight boards without breaking any law or contract with you, and would not have to honor your request to travel on a non-MAX aircraft instead.
This article is less compelling than the title would suggest.
After the Lion Air crash the FAA released a Emergency Airworthiness Directive, these five comments are in response to that directive. That differentiates it from pilots that had a negative run-in with MCAS or other defects in the 737 Max 8 (which would be significant news).
This article might inform you pilots are unhappy, but that fact has been widely circulated elsewhere since the Lion Air crash. The fact that five pilots submitted official comments doesn't add to what we knew.
These comments for example wouldn't have helped inform the FAA's decisions, since the FAA told the pilots about the issues in the Emergency Airworthiness Directive that these comments are based upon.
The Dallas News report shows two separate complaints where the pilots knew of and discussed MCAS on the flight deck before take off and still had serious problems with it.
"Boeing Co. withheld information about potential hazards associated with a new flight-control feature suspected of playing a role in last month's fatal Lion Air jet crash, according to safety experts involved in the investigation, as well as midlevel FAA officials and airline pilots."
"Safety experts involved in and tracking the investigation said that at U.S. carriers, neither airline managers nor pilots had been told such a system had been added to the latest 737 variant — and therefore aviators typically weren't prepared to cope with the possible risks."
If I am reading the article correctly, the complaints all came after JT610? It would have been more damning if they had been complaining about this for the last couple years.
man fuck canada and the usa. how are we the only ones in the world to not care about safety. even if its a 0.5% chance 150+ people die, isn't that enough to warrant temporarily grounding a handful of planes. sigh common
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.
[+] [-] tuna-piano|7 years ago|reply
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=546686797940621...
DOC - http://s000.tinyupload.com/index.php?file_id=726497188798253...
[2] Airplane model filter with no MAX option: https://imgur.com/a/09rRtzX
[3] ASRS database: https://titan-server.arc.nasa.gov/ASRSPublicQueryWizard/Quer...
[4] Document linked in the article with plane models listed under 737-800 or 737-Next Generation Undifferentiated https://www.documentcloud.org/documents/5766398-ASRS-Reports...
[+] [-] sfilargi|7 years ago|reply
Notice they have never briefed you about this new system because they didn't want to retrain you.
You happily drive along the highway at 70mph when the system malfunctions and incorrectly thinks the car is over-steering left, so the steering wheel starts rotating clockwise. The car swiftly moves to the lane in your right as you use all your strength to prevent it and manage to bring the car back in the lane.
In the mean time all kind of lights and sounds go off on your cockpit. In 5 seconds, while you are trying to find out what to make out of all the lights flashing, the steering wheel starts turning the card right again. This time you are not so lucky and you crash into the truck on your right.
[+] [-] rootusrootus|7 years ago|reply
At least you don't have to get a new endorsement on your license for every model of car.
[+] [-] lsh123|7 years ago|reply
[+] [-] dmead|7 years ago|reply
[+] [-] ergocoder|7 years ago|reply
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?
[+] [-] lutorm|7 years ago|reply
That doesn't discount the fact that most of the risk is in take-off/landing, so if you use fleet-average statistics you'll bias the risk of short flights low and long flight high. Air safety studies do also use additional metrics like accidents/hour and accidents/segment, but those are mostly useful for comparing between different types of aviation.
[+] [-] nicktelford|7 years ago|reply
Ignoring the silly ones (Space Shuttle, Skidiving and Paragliding), we see that Motorcycles are by far the most dangerous mode of transport, across all metrics. Buses do very well, only losing out to Aircraft on distance.
When you look at Aircraft by number of journeys, the risk is significantly higher - nearly 3 times higher than car journeys!
That said, there are othe factors to consider here: these metrics only track _deaths_. So non-fatal incidents (of which the majority involving cars are) aren't considered.
[+] [-] upofadown|7 years ago|reply
I would point out that in a similar way few people drive between continents but flight is common.
[+] [-] azernik|7 years ago|reply
[+] [-] reneherse|7 years ago|reply
[+] [-] Udik|7 years ago|reply
[+] [-] paxys|7 years ago|reply
[+] [-] mrhappyunhappy|7 years ago|reply
[+] [-] pfortuny|7 years ago|reply
[+] [-] mannykannot|7 years ago|reply
IIRC, after the existence of MCAS was disclosed, the US pilots' unions were divided over this issue, with the union representing Southwest pilots castigating Boeing for its nondisclosure, while that representing United pilots did not consider it to be a big issue. Unfortunately, this article does not make it clear where pilots stand on issue 3, and the investigation of the Ethiopian Airlines crash might reveal additional issues.
The forthcoming software upgrade for MCAS certainly implies that there were improvements to be made.
[+] [-] blackflame7000|7 years ago|reply
https://theaircurrent.com/aviation-safety/what-is-the-boeing...
[+] [-] tuna-piano|7 years ago|reply
Not according to Boeing... "Boeing has been developing a flight control software enhancement for the 737 MAX, designed to make an already safe aircraft even safer."[1]
To me an incredibly infuriating statement. The 737-MAX has a fatal crash rate of ~4 per million, when compared to .1 per million for the 737-NG models (40x). There is no currently flying major commercial aircraft which has a higher fatal crash rate than the 737-MAX [2] [3] Of course the MAX has a small sample size, but that's still not evidence of safety.
What data is Boeing looking at to show that their aircraft is considered a safe aircraft?
[1] https://boeing.mediaroom.com/news-releases-statements?item=1...
[2] https://finance.yahoo.com/news/boeing-737-crashes-liability-...
[3] http://www.airsafe.com/events/models/rate_mod.htm
[+] [-] jahewson|7 years ago|reply
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.
[+] [-] ddoolin|7 years ago|reply
My question is, should the onus be on the pilots? Yes, they should know about it if they're going to be piloting an aircraft with it, but is this expected behavior? To me it seems more like a bug than expected behavior...why would you want to pitch downwards in a climb?
I don't really understand defense of Boeing in any scenario. This seems like a mistake in any case, whether it's just lack of instruction or documentation in the relevant flight manuals, or an outright system failure.
[+] [-] unknown|7 years ago|reply
[deleted]
[+] [-] yason|7 years ago|reply
To the uninitiated, it seems that problems in airline incidents used to revolve around mechanical failures, bad wiring, sensor malfunctions, toasted electronics causing smell of smoke and such. Plain and simple. Issue a fix in the design and apply to all planes of the same type, and you'll end up reducing the failure surface bit by bit.
I might be totally wrong about this because I don't track actual data. But if I've spotted the trend right it's scary because the problems are shifting into our space, i.e. software engineering. And being a software engineer, I know we're pretty much fucked at that point. We've only ever managed to write reliable and trustworthy software when we've split it into very tiny pieces that we can verify and kept the number of pieces small.
Maybe aviation computers used to be much simpler that they could be verified more throughoutly. Maybe airplanes used to have less features and they could keep the complexity sufficiently down and functionality orthogonal. Maybe there was enough human glue in between the systems so that there was a live sanity-check during flights and pilots could react properly if the computers didn't agree on something.
But now I sense a new category of error conditions that are eerily similar to what we've had in non-critical software for decades where assumptions are laid on top of other assumptions, and when they fail the whole stack comes crashing down. Only this time there might be a whole plane coming down instead of getting a curious SIGSEGV on the screen with a blinking cursor. It might start as an innocent "couldn't access flight plan because of wifi went down" but such interdependencies between certified and uncertified systems grow exponentially and this will snowball into the unmanageable very soon.
[+] [-] jcroll|7 years ago|reply
Is this a lot?
[+] [-] alfalfasprout|7 years ago|reply
[+] [-] tuna-piano|7 years ago|reply
In addition, it seems like some pilots were motivated to submit reports on their MAX experiences due to the Lion Air incident.
[+] [-] rconti|7 years ago|reply
I'm appalled at Boeing's response, and I agree with the Europeans, other countries, and Senator Cruz and others that the planes should probably be grounded, at least very briefly.
But the news reporting that an unknown-relative-to-other-planes percentage of complaints were filed by pilots, especially when those reports could theoretically be merely annoyed pilots responding to a perceived lack of training, or piling on after Lion Air, doesn't tell me a whole lot I didn't already know.
[+] [-] qrbLPHiKpiux|7 years ago|reply
[+] [-] CodeSheikh|7 years ago|reply
[+] [-] cjbprime|7 years ago|reply
This is not actually any kind of right in the US. The airline can switch to using a MAX just before the flight boards without breaking any law or contract with you, and would not have to honor your request to travel on a non-MAX aircraft instead.
[+] [-] tommoor|7 years ago|reply
[+] [-] Someone1234|7 years ago|reply
After the Lion Air crash the FAA released a Emergency Airworthiness Directive, these five comments are in response to that directive. That differentiates it from pilots that had a negative run-in with MCAS or other defects in the 737 Max 8 (which would be significant news).
This article might inform you pilots are unhappy, but that fact has been widely circulated elsewhere since the Lion Air crash. The fact that five pilots submitted official comments doesn't add to what we knew.
These comments for example wouldn't have helped inform the FAA's decisions, since the FAA told the pilots about the issues in the Emergency Airworthiness Directive that these comments are based upon.
[+] [-] mimixco|7 years ago|reply
[+] [-] V-eHGsd_|7 years ago|reply
[+] [-] int_19h|7 years ago|reply
[+] [-] acqq|7 years ago|reply
"Boeing Co. withheld information about potential hazards associated with a new flight-control feature suspected of playing a role in last month's fatal Lion Air jet crash, according to safety experts involved in the investigation, as well as midlevel FAA officials and airline pilots."
"Safety experts involved in and tracking the investigation said that at U.S. carriers, neither airline managers nor pilots had been told such a system had been added to the latest 737 variant — and therefore aviators typically weren't prepared to cope with the possible risks."
https://news.ycombinator.com/item?id=18438607
[+] [-] rootusrootus|7 years ago|reply
[+] [-] FigBug|7 years ago|reply
[+] [-] neonate|7 years ago|reply
[+] [-] doctorshady|7 years ago|reply
[+] [-] nothrows|7 years ago|reply
[+] [-] kenneth|7 years ago|reply
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.
[+] [-] purplezooey|7 years ago|reply
[+] [-] objektif|7 years ago|reply
[+] [-] woofcat|7 years ago|reply
Sometimes clustering occurs, such as Maylasian airlines being shot down and lost in an ocean and never found. We didn't ground the whole airline.
[+] [-] infinity0|7 years ago|reply
What, except for the data of the two crashes happening? The person that wrote this statement is a fucking idiot.
[+] [-] toweringgoat|7 years ago|reply
Please learn some basic geography. Norway (and Switzerland) are not in the EU.
[+] [-] AnabeeKnox|7 years ago|reply
[+] [-] yeukhon|7 years ago|reply
[+] [-] tibbydudeza|7 years ago|reply
[+] [-] known|7 years ago|reply