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Comment by tuna-piano | Hacker News Reader

Sympathies for all the victims and their families, incredibly sad.

Many of us have heard the phrase "If it ain't Boeing, I ain't going." In reference to Boeing's perceived safe planes. This phrase has lost any meaning to me, and in fact, I'm feeling the opposite way right now.

Boeing's response to the first 737-Max Lion Air crash was abhorrent, in my opinion. While they were taking the time to blame the Lion Air pilots reaction to the plane's issue, and stating how safe the 737-max was, they were also working on urgent patches to their software. The patch is still not yet deployed, but the planes continue to fly.

If initial info of this crash points to a related cause to the Lion Air crash, anything less than a full grounding of all 737-Max aircraft seems incredibly dangerous. I get the feeling that Boeing executives have checked their better moral judgement at the door and are thinking solely in terms of dollars.

I can't help but feel that Boeing and US regulators would have taken the issue identified after Lion Air much more seriously and been much more likely to take action and responsibility if it was a US flight. That thought leaves me with incredibly sour taste in my stomach.

For those who may come to Boeing's defense, take a look at how pilots of the 737 Max responded to the Lion air crash - often with anger.

[1] https://www.nytimes.com/2019/02/03/world/asia/lion-air-plane...

[2] https://www.washingtonpost.com/business/2018/11/13/pilots-un...

[3] https://www.fullwsj.com/articles/regulators-push-for-clarity...

[4] https://www.fullwsj.com/articles/boeing-and-regulators-delay...

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We can't afford to wait for evidence proving beyond a reasonable doubt that this aircraft is dangerous.

Probable cause should be a sufficient standard.

Two crashes in similar circumstances is probable cause to take them all out of service until they figure out what the hell is going on.

For myself and my family, we won't wait for regulators and airlines to act. We will not fly the 737 Max.

It's interesting that you reach that conclusion.

I'll fly 737 max.

I won't fly Lion Air or Ethiopian Airlines.

Southwest: fleet size 754, founded 1967, total of seven accidents with 3 deaths.

Ethiopian Airlines: fleet size 107, 64 accidents with 459 deaths since 1965.

It is possible for both a carrier to be more at-risk for crashes as well as a plane to be more at-risk for crashes.

The FAA issued an emergency operation directive for the 737 Max due to inaccurate sensors which could lead to a crash. I'm not entirely sure why you're ignoring that fact and deflecting to something unrelated.

> deflecting to something unrelated

I don't think it is unrelated that the only accident thus far of a plane with a failure mode that is more difficult for pilots to respond to was on an airline with a notoriously bad safety record.

I fully recognize the fact that airlines and pilots were not informed well enough about MCAS, but I'm also not ignoring the other circumstances of lion air 610

Safety in depth - a single failure should not be a problem. 610 crashed as a result of MCAS, but also a number of other operational failures of Lion Air and the pilots.

If Boeing is issuing software updates that disable manual override without telling pilots, Boeing is completely at fault here, and some of the engineers/executives should face criminal charges.

> criminal charges

Boeing informed the FAA of the changes, and the FAA decided that the pilots and airlines did not need to be informed. Criminal charges for Boeing would be extremely surprising.

Would the FAA decision have any bearing on what happens in Ethiopian airspace?

Good point. Boeing should be have told every customer that bought a plane.

Taking your question at face-value: FAA guidelines apply to all airlines that fly into the US - Ethiopian does.

I am confused. When I read the article about the Lion Air crash, I thought one cause of the crash was that the pilots hadn't been properly trained in the manual override procedure that can deal with the problem with malfunctioning sensors.

I don't understand how a software update can override a completely manual override.

The procedure that pilots are taught to override auto trim was unchanged, but I think that previous auto trim systems could also be "out muscled" just by pulling back on the yoke without actually switching on the manual override. It's that second part that people are pointing out (though I will in turn point out that the pilots on the flight prior to 610 faced similar issued and used the manual override to respond to them).

I think accidents per trip (flight leg) is a more useful metric than accidents per year. If you're interested in mechanical issues then you'd also need to remove terrorism related deaths.

Yes, it's a small sample size, but if you look at the fatal accident rate per flight leg of a 737 MAX 8, I'm sure it's much higher rate than any other modern aircraft.

According to https://www.tripsavvy.com/the-safest-aircraft-54428, the following modern aircraft have fatality-free records:

Boeing 717 (formerly the MD95)

Bombardier CRJ700/900/1000 regional jet family

Airbus A380

Boeing 787

Boeing 747-8

Airbus A350

Airbus A340

This list is meaningless without accounting for the number of aircraft & the number of miles they have flown. For example, the 737 is not only the world's most popular commercial airliner, it's simultaneously the "most dangerous plane" because it has had 145 accidents [1] and one of the safest planes because the 737 NG variant has only had one crash in 16,047,900 flight hours. [2]

[1] https://www.airfleets.net/crash/stat_plane.htm

[2] http://www.travelvivi.com/the-safest-aircrafts-in-the-world/

And indeed, the 787, 747-8, A350 and arguably the A380 are all new planes that have not accumulated the decades of flight history with huge fleets that the 737 has.

True, but the 737 MAX 8's first commercial flight was in 2017, much newer than any of the aircraft on the above list. The point is that such a new aircraft already has a far worse safety record than plenty of aircraft that have been around for years. I think it's irrelevant to compare 737 subtypes, since discussion focuses on the 737 MAX 8 variant specifically.

> And indeed, the 787, 747-8, A350 and arguably the A380 are all new planes that have not accumulated the decades of flight history with huge fleets that the 737 has.

The 787's first commercial flight was in 2011. The 747-8 in 2012. A350: 2015. A380: 2007. All predate the 737 MAX 8 by years, and have better safety records.

Sure, but for comparison, the original 737 was launched in 1967 (!) and even the 737 NG has been flying since 1997.

So while having two MAXes crash after takeoff mere months apart is indeed statistically unlikely, I wouldn't necessarily leap to the conclusion that the two accidents are related just yet.

You have to know that the problematic Anti-Stall feature was just recently added in the MAX rev 8. The older rev 1-7 don't have it. It might have other stall problems due to being backheavy, but the traditional stall warning should have been good enough. There was no accident in rev 1-7, none with the improved Southwest configuration (with two sensors) and already two complete losses with the updated MCAS rev 8. They already did two more updates on this (9 and 10), but still not safe enough for modern safety standards.

The Concorde used to be #1 on this list, while being the least safe commercial jetliner of all time.

Good luck flying Southwest in Africa.

You write as if you always have a choice which airline to use. Southwest is mainly USA domestic with a few vacation destinations nearby USA.

I don't have data on flight miles or flight segments by type of aircraft, so let's do a quick and dirty estimate.

Let's say there are 40,000 commercial aircraft worldwide and 350 of these are the Boeing 737 Max [0].

If all aircraft are equally likely to crash, then the probability of a given crash being a 737 Max is 350/40000 = 0.00875.

The probability that two crashes are both 737 Max is 0.00875 * 0.00875 = 0.0000766

It's extremely unlikely that an aircraft representing less than 1% of the global fleet would crash twice in a short period of time unless there is a serious defect with that aircraft.

That's well past probable cause at this point. This aircraft should be grounded until they figure this out.

[0] https://en.wikipedia.org/wiki/List_of_Boeing_737_MAX_orders_...

Active fleet today: https://twitter.com/flightradar24/status/1104838043792490497

> The probability that two crashes are both 737 Max is 0.00875 * 0.00875 = 0.0000766

You need to multiply this by every combination of two crashes in the observed time period with starting and endpoints not cherry picked to include 737 max crashes though.

Be my guest. You'll find that the probability of a rare aircraft crashing twice in a short period of time is infinitesimal, unless that aircraft contributed to the catastrophe.

It's hardly infinitesmal, that's my point.

With an average of 175 737's operating since launch, 4K total widebody commercial aircraft and over a dozen widebody crashes in that period, you get over 10%. Some estimates there but you still have the endpoint issue as well.

There have been a total of 5 commercial air disasters in 2018 and 2019 with fatalities that didn't involve hijacking, landing short of the runway or overshooting the runway [0].

And that includes the crash of a cargo flight with no passengers where the crew was killed.

The 737 Max 8 was involved in 2 of those 5 disasters.

There are between 25,000 and 39,000 commercial aircraft in service depending on who you ask [1].

With 350 737 Maxes delivered so far, that's at most 1.4% of the total today, probably less than half that this time last year. Let's call it 1% on average for 2018 and 2019 combined.

There are 10 ways you can have 2 Max crashes out of 5 total crashes. So the probability is 10 * 0.01^2 * 0.99^2 = 0.00098

Even accounting for n choose k and longer endpoints, it's still an infinitesimal probability that we'd see two catastrophes with the same rare aircraft -- unless that aircraft contributed to the catastrophe.

It should be grounded.

[0] https://en.wikipedia.org/wiki/List_of_accidents_and_incident...

[1] https://www.telegraph.co.uk/travel/travel-truths/how-many-pl...

Southwest also took steps to add additional AoA sensor information displays to their 737 Max aircraft in the wake of the Lion Air crash. The operator does make a difference.

https://theaircurrent.com/aviation-safety/southwest-airlines...

Downvoted. Your data is terrible and should be cited. The 737Max has only been flying for 2-3 years. Southwest is irrelevant (I say as I sit on a SWA flight on the tarmac in SAN waiting for a replacement crew member). I made damn sure it wasn’t a Max (which I flew on Aeromexico twice back in September).

I have no idea where your Ethiopian stats come from because I’ve heard nothing but great things about them. Feel free to rebut.

“Or how about Ethiopian Airlines? Here is another impoverished country surrounded by rugged terrain. Yet the record of its national carrier — three fatal events, one of them a hijacking, in over seventy years of operation — is exceptional. Ethiopian is one of the proudest and arguably one of the safest airlines in the world.”

http://www.askthepilot.com/questionanswers/foreign-airline-s...

Unable to delete, as I was able to find stats last night that confirm Parent's Ethiopian Air stats, and I regret the tone.

Regardless, Ethiopian Air is considered a top tier safe carrier.

But Southwest did something nobody else did. They added a second AOA sensor. This should mandatory by every security standard and Southwest did good by mandating it, but Boeing still got away with all other companies.

It will take mere days to determine definitively if the crashes involved the same trim system.

I think you are completely free to avoid the 737 MAX as long as you like, but it seems like panic and hysteria to call for a widespread public reaction before any actual crash data is available.

Quite the opposite. In lie of facts one should err on the side of caution. So far the similarities to the previous accident are striking. The whole fleet should be grounded immediately.

If you fly an airline with MAX 8's in fleet, you can show up at the gate and find out it's a MAX 8 when it wasn't previously scheduled, and it will not be free for you to avoid that flight.

It doesn’t make sense to me how they can continue blaming pilots if the cause of today’s crash is the same as last year’s. Even if they tell us with undisputable evidence that the plane was operating within standard operating procedure, it sounds like that SOP is unintuitive garbage and putting everyone at risk. The latter part is what matters the most. I don’t see any sane or reasonable path other than grounding the 737 Max.

I have no expertise in the area, but I doubt it's the same cause. Every 737 Max pilot will certainly be aware of the Lion Air crash and the ways to mitigate that particular behavior of the aircraft.

We need to wait for the investigation before we jump to conclusions.

>Every 737 Max pilot will certainly be aware of the Lion Air crash and the ways to mitigate that particular behavior of the aircraft.

I think that is a good point.

Not necessarily.

The 737 Max is the same type rating as all other 737. That means the pilots and crew switch back and forth between the Max and non-Max planes — despite the fact that they act very different in certain circumstances.

This was intentional, it saves airlines money to have fewer type ratings.

Besides, so soon after take off there’s very little time to recover when your plane is overriding you attempts to keep it from nose diving into the ground. It’s not as simple as flipping a single switch.

Why arent pilots able to take full and absolute control of a plane at any time whatsoever?

What does "full and absolute control" mean in the context of a fly-by-wire aircraft? AA587 is blamed on a pilot's inputs driving a structural capability exceedance in the vertical stabilizer. For reasons such as these, all fly-by-wire aircraft will have some measure of envelope protection whereby pilot inputs projected to exceed aircraft capability will be limited. There is always "interpretation" of pilot inputs involved in fly-by-wire systems. The key is in making available all control power to the pilot that will not result in catastrophic structural failure of the aircraft. And the associated challenges are knowing exactly where those boundaries should be set in the design of the control system, as well as the knowledge of the aircraft state to the flight computers.

Thank you for the extensive response. With that context, I would say "full control" should amount to the ability of a pilot to overrule systems that may send an aircraft nosediving due to faulty sensors.

Did the pilots of the Lion Air flight and possibly the Ethiopian Air flight understand what was wrong in-flight and were unable to fix it due to an inability to override aircraft controls?

This is what I am getting out of the discussion so far but maybe I am gravely misunderstanding what's happening? So as a passenger without any knowledge of aviation systems my question is merely whether the pilot gets control over the aircraft when he demands it? Fly-by-wire should at least never lead to autopilot suicide, even if it has to ensure flight integrity to a certain degree due to the technical nature of large, modern aircraft.

We demand this level of conscious awareness and control of 4-5 year old children in our society but machines that carry dozens of lives are not held to such a standard of attention and interaction. This might be something that AI can address, but most current offerings still lack features we consider essential for even very young children.

> Thank you for the extensive response. With that context, I would say "full control" should amount to the ability of a pilot to overrule systems that may send an aircraft nosediving due to faulty sensors.

Thanks for reading it :) . As you phrased it specifically, I can't disagree with you. But in these systems, the devil is in the details. For Boeing's MCAS, which is like an add-on piece of functionality to the core control system, it seems like an obvious piece which should have a manual override - and it does. The criticism, as I understand it based on Lion Air, is that the override functionality is not obvious and if you were previously a 737 pilot on non-Max variants, you might not know about this or have practiced its use.

However, consider safety systems such as Automatic Ground Collision Avoidance System ("Auto GCAS") or Automatic Air Collision Avoidance System ("Auto ACAS"). These systems are designed as reactions to multiple known cases of human error that have resulted in otherwise under-control aircraft being flown into the ground or other aircraft. They are specifically designed to override a mistaken human. Technically, it's not impossible that pathological failures or spoofing could trigger these automated systems, which would wrest control away from pilots. Should such systems be overridable at all times?

Resolving these kinds of issues does involve some judgment and adopting a philosophy prior to the implementation. Airbus and Boeing, for example, have historically differed in their philosophies, each with reasonable rationale.

I personally favor the approach Boeing has historically used, with AF447 and QF32 illustrating some of the pitfalls of Airbus' approach. For example, as pointed out by ggreer in https://news.ycombinator.com/item?id=19355402 , being susceptible to common mode faults.

However, I still fly on either manufacturer's aircraft without hesitation.

> It’s not as simple as flipping a single switch.

Except that's exactly what it is and then manually setting the trim. The NY times had an excellent article about the procedure:

> The crucial step, would be to reach across to the central console to a pair of switches, and flip the switches off. Those switches disable electric control of the motor that moves the stabilizers up and down, preventing the anti-stall system from exerting control over their position.

https://www.nytimes.com/interactive/2018/11/16/world/asia/li...

If you're used to flying a plane for several thousand hours that's not going to be second nature at all (when the procedure has changed).

You really should watch this video just to get an idea of how catastrophic this error is:

https://youtu.be/baK39CrgW-4?t=363

Not sure what I'm meant to glean from that video? It's the last 10 seconds of the flight?

The lion air pilots had 15 mins to disable the automatic trim system and simply set the trim manually. It's turning off a switch and spinning a wheel. Manually setting trim is second nature to student pilots.

They should also have read the log prior to departure and seen the previous four flights had this problem that did exactly this. Quite sure pilot error will be the outcome for lion air.

There's absolutely no difference in procedure here a normal 737. Unsure where you got that idea from.

Perhaps how catastrophic this issue could be while the flight is still in low altitude during one of the busiest phases of operations?

The procedure to set the trim manually was the same, but I assume that in most flights the actual flywheel is never turned by hand (and thus rarely deactivated). I'm sure most pilots use the fly-by-wire systems or autopilot.

The procedure which was different was the automated MCAS system - pilots who have logged significant hours flying the previous model of 737 would be unprepared for this during an extremely busy phase of the flight.

Ultimately, yes, it was the pilots error when they didn't take the proper actions when the problem first occurred. Nevertheless, we must first take into account why the automated system failed to begin with, and why the pilots made the error (lack of training, sleep, preparation).

This isn't binary, and the fact Boeing is issuing a patch for the software systems as a direct result of Lion Air tells me there is more to the story than just "pilot error".

Sensors fail all the time modern aircraft, people would probably be quite scared knowing how often.

After the Airfrance airbus incident they also introduced a "patch" to protect the aircraft from erroneous pilot actions leading to stalls when indicators are incorrect, those fixes were certainly not indicative of guilt but just another layer to stop pilots making mistakes.

To put it bluntly only a fool is going to start flipping switches willy nilly. Boeing has a procedure out to handle runaway stabilizer trim, and that's to flip the switches, but the Lion Air pilots did not encounter a runaway stabilizer so why would they go down that checklist and potentially add to their troubles? In the case of the cutout switches, those switches do different things on the NG and MAX (and are thus labeled differently) which potentially adds to the confusion and reduces the incentive to experiment. You're talking about counteracting a system that Boeing hid from pilots — hardly pilot error.

In fact if you look at the FDR data you'll see that the pilots were able to temporarily disable MCAS with the trim buttons on the yoke. Every time MCAS trimmed down, the pilot trimmed up and was able to maintain appropriate trim. That worked, and it seemed like the plane was largely under control (until it wasn't).

Meanwhile the unreliable airspeed indicators were illuminated and one of the stick shakers was going off, and there was probably an EICAS message about the elevator feel system but no actual indication of the underlying problem with AoA was given because Boeing charges extra for that. So, with the assumption that you had the stabilizer trim under control, why would you add to the significant workload by disabling the electrical control of the stabilizer?

> with the assumption that you had the stabilizer trim under control, why would you add to the significant workload by disabling the electrical control of the stabilizer?

I'm struggling to see how you think having to make manual adjustments every 30 seconds is "under control". Check the flight profile, it was never under control.

> the Lion Air pilots did not encounter a runaway stabilizer

What did the pilots on the four previous flights encounter? Did they not follow procedure correctly by overriding it? The trim stabiliser had to be adjusted 23 times during the the fatal flight, this is a solid fact. After a few times it should have been very apparent that there was a problem related to the automatic trim system and switched to manual.

Manual trim would only get adjusted a only few times during a regular flight, it's a very basic skill and the trim wheel itself takes up a huge amount of real estate in modern cockpits.

Sorry but you've written a lot of terribly inaccurate stuff here. Let's see what the report says.

There are dozens of design flaws in modern aircraft, a miniscule amount are unrecoverable following procedure.

The process to manually override trim on a 737 that should have been followed:

https://www.nytimes.com/interactive/2018/11/16/world/asia/li...

I'm struggling to see how you think having to make manual adjustments every 30 seconds is "under control". Check the flight profile, it was never under control.

Every time MCAS trimmed down, the pilot trimmed up which resulted in two things: MCAS stopped trimming down, and the stabilizer was adjusted up. That's not a runaway situation.

What did the pilots on the four previous flights encounter?

The previous pilots ran into MCAS trimming the stabilizer down inappropriately. They wrote it up as a speed trim (STS) failure. The crew on the fatal flight read STS and was probably thinking STS when they crashed. Unlike the undocumented MCAS inputs, STS can be disabled by moving the control column.

Did they not follow procedure correctly by overriding it?

There was no procedure, MCAS was undocumented.

Manual trim would only get adjusted a only few times during a regular flight

You're almost never going to crank the trim wheels by hand but an NG pilot may be used to having to add input to counter STS.

The process to manually override trim on a 737 that should have been followed:

The pilots were presented with more than just uncommanded trim adjustments, they were presented with multiple, seemingly unrelated, failures. The failed AoA measurement meant they had no idea how fast they were going (new behavior on the MAX, see the repeated queries they made to the ATC), one of the stick shakers was going off (unsure if plane is going to stall and fall out of the sky), and there was probably a warning about the "elevator feel" system on EICAS like on the previous flight.

When faced only with uncommanded trim, sure, they probably would've thought STS because that's the only system Boeing bothered to document. In an ideal world the pilots would've recognized that this wasn't STS. In reality the pilots were busy triaging a variety of symptoms because Boeing did not make appropriate warning / status indications standard equipment on the MAX nor did Boeing actually document that MCAS exists (except in Brazil).

The only error that the Lion Air crew made was in not being clairvoyant.

That's like suggesting that once a patch exists for a vulnerability in software that tye vulnerability no longer exists.

Dissemination of information about a risk is an entirely separate issue from creating a solution to the underlying flaw.

Nope. We ground the planes until we figure out what’s wrong. There is simply too much risk in “not jumping to conclusions,” unless you wouldn’t mind the deaths of a couple hundred people on your head?

My guess is that it's related to Indonesia's poor historical air safety record. This goes for ferries, buses and trains as well. Penalties for not ensuring safety are far too lax hence this cycle continues.

But I understand in this case we are talking about a brand new aircraft.

Sounds like 737-Max has an inherent design flaw that they tried to patch with a software fix adding unnecessary complexity, a single point of failure(AoA sensors) and more importantly adds an element of surprise for the pilots:

https://theaircurrent.com/aviation-safety/what-is-the-boeing...

Basically pretty shitty system design.

> Many of us have heard the phrase "If it ain't Boeing, I ain't going."

Do people out there really think Airbus have such lower safety standards that they won't fly on them? They must struggle to get around even the US domestic routes these days.

Isn't this a reference to airplanes like MD DC-10? Airbus is a super new company.

> Airbus is a super new company.

Not really sure what you're on about - Airbus' passenger jets started only a decade after McDonnell Douglas and Boeing's. A300 flew around 1970. DC-8 flew around 1960, same as the Boeing 707.

Th grandfathers of some people on this site would have been flying on Airbus.

> The grandfathers of some people on this site would have been flying on Airbus.

I like the image, but I think you can make it much stronger. The grandfathers of many users of this site are still flying on Airbus (as well as all other current planes), so I think you being at least a couple generations to conservative. Instead, I think it's safe to say that the "great-great-grandfathers" of some of the users of this site almost certainly flew on an Airbus.

For ease of math, assume an 18 year-old-user born in 2000, 25 years per generation, and a 75 year lifespan. Their father was born in 1975, their grandfather in 1950, their great-grandfather in 1925, and their great-great-grandfather in 1900. That great-great-grandfather died in 1975, and thus assuming they flew in the last years of their life, would likely have flown on an A300.

Given that these assumptions might be closer to average rather than extreme, I don't think it would be unreasonable to bet that at least one user's great-great-great-grandfather flew on an Airbus as well.

You are right, Airbus is not as new as I thought. Still I think it was a reference to DC-10?

And not just Airbus. Hard to imagine how you're going to do much regional travel and avoid Embraer, Bombardier, or ATR.

> If it ain't Boeing, I ain't going

No one actually says that. Even Boeing itself, when arranging corporate travel for employees, picks whatever flight is available with reasonable airfare regardless of aircraft type.

It’s a common saying in the northwest. If not actually obeyed.

Another bad Boeing response in 1991 - https://en.wikipedia.org/wiki/Lauda_Air_Flight_004#Niki_Laud...

Yup Boeing has lost its way and is another typical bureaucratic hell hole of a company like IBM. I’ve heard horror stories about the 787 development process as well.

There was a quip back in 1997 that "McDonnell Douglas bought Boeing with Boeing's money" referring to the restacking of the Boeing management with ex-McDD executives after the merger.

The last true engineering-led Boeing was the 777. Chaotic mess of 787 development or apparent stretch-too-far Max are pure McDD.

I flew the 737 Max about a month after the Lion crash. I sure as hell will not be getting on it anytime soon.

I completely agree and I was utterly shocked when so many “self-professed experts” on HN just dismissed everything to accuse the pilots that didn’t read the manual. As I said before I will not fly on a 737 max until all this shitshow is cleared, and I urge everyone else to avoid it.

I checked my next flights, some Airbus, a Fokker and two 737-800. Luckily not the MAX. I never checked the aircraft model before booking but I'll start doing it. I won't fly a MAX.

Better to be safe than to be sorry, especially when your life is at stake.

The airplane can be changed at the last minute, but it's worth a try I guess.

I’m curious why they would need that system in the first place. Pilots know to trim for level flight so the computer doing it automatically seems unneeded regardless of new engine placement.

The new system (MCAS) was not intended to take action in normal flight. It was intended the trim in certain scenarios (roughly high AoA + steep turn + high g + near stall), but on lion air 610 the AoA sensor was malfunctioning, which caused MCAS to activate when it shouldn't have.

The engines are more powerful and further ahead of the wing on the MAX. This means that the plane may pitch up significantly (and potentially stall) if you apply a bunch of thrust. MCAS was designed to prevent this.

There was, IIRC, a similar incident in an 737 Classic (go around in England that achieved a dramatic nose up pitch IIRC — not the Tailwind incident) but I can't seem to find the entry on avhearld.

You're probably referring to this one - Thomson 737-300 at Bournemouth in 2007. Scary reading the full report: 44 degrees nose-up and 82 knots indicated air speed!

https://www.gov.uk/aaib-reports/aar-3-2009-boeing-737-3q8-g-...

Yep, that's the one. If memory serves, most or all planes with the engines under the wing will pitch up when you apply thrust. Most planes will have an effective enough elevator to counteract this... but it seems like the 737 does not.

"if it was a US flight."

Or Airbus.

> If it ain't Boeing, I ain't going

I have mostly had the reverse sentiment; my experience is mainly based on 777-xxx planes, but I find the experience in those so horrible that I try to avoid Boeing in favor of Airbus. Every time when I cannot (like last week when I flew with a 777-300er) I get reminded how crap these things really are. Not talking safety but general feel and comfort; basically everything is worse; noise, seating, effects of turbulence etc. And I have noticed this across multiple premium airlines.

I also wonder if the fact that Boeing is a US company has anything to do with it. If this was an Airbus would the US have required grounding of the planes? I believe your point about if it happened in the US they would still have been grounded but perhaps if it wasn't a US company they would have pushed for grounding to be safe even if it did not occur in the US.

US never grounded Airbus, but grounded all Boeing 787s once.

Lion Air wasn't maintaining their aircraft well. The new anti-stall feature that seemed to cause the Lion Air crash shouldn't have activated under a sensor fault scenario, yes, but software alone isn't to blame for that one.

The Lion Air crash was a 2 months old plane. I'd expect a 2 months old plane to be air worthy even if some maintenance was neglected.

But they neglected maintenance when serious issues with the plane were apparent. The pilots of the flights prior to 610 noted that the two AoA sensor readings differed by ~20 degrees, and nearly aborted their flight before overriding the auto trim.

Flight 610 should never have taken off.

That's a misstatement of what occurred. The aircraft had a fault on the previous two flights and was repaired before the fatal flight.

> Flight 610 should never have taken off.

A repaired aircraft should not take off?

The preliminary report from the investigation of LNI610 disagrees with you: https://reports.aviation-safety.net/2018/20181029-0_B38M_PK-...

The AoA attack sensor was replaced prior to flight LNI043 (he flight prior to 610), in which the pilots declared pan-pan and had to manually override the auto trim systems (which include MCAS). Between 043 and 610, there was further maintenance that included flushing the pilot valves and cleaning electrical connectors, but the AoA sensor was not replaced between 043 and 610.

An aircraft that was repaired followed by one flight in which the pilots declared abnormal operation and performed 3 non-normal checklists should probably not fly again until they figured out what happened, and the next flight should definitely be aware of the incident on the flight prior. 043 faced and overcame the exact same malfunction as 610 - to me that indicates a clear failure. If you keep flying an aircraft that malfunctions on each flight, you're pressing your luck.

> Between 043 and 610, there was further maintenance that included flushing the pilot valves and cleaning electrical connectors, but the AoA sensor was not replaced between 043 and 610.

They followed Boeing's procedure in attempting to address the issue again (after already replacing the sensor). That's a completely appropriate action.

> the next flight should definitely be aware of the incident on the flight prior.

It is in the log book. Is this a reference to something particular?

> 043 faced and overcame the exact same malfunction as 610 - to me that indicates a clear failure.

I agree, that's why maintenance conducted a repair.

> If you keep flying an aircraft that malfunctions on each flight, you're pressing your luck.

They attempted two repairs in accordance to the manufacturer's procedures within that time in order to resolve the malfunctions.

This post references the report and you clearly read it enough to know your original conclusion was mistaken, but are still arguing you're right by trying to shift the discussion. You've gone from "they flew a broken aircraft" to "alight, so they repaired it twice, but you cannot ever trust a malfunctioning aircraft again." By that logic every single commercial aircraft would be in the junkyard... Repairing malfunctioning systems is normal, attempting two different repairs isn't uncommon either.

> You've gone from "they flew a broken aircraft" to "alight, so they repaired it twice, but you cannot ever trust a malfunctioning aircraft again."

If you think I've changed my argument, you misunderstood my comments. I still think that they flew a broken aircraft.

I'll stand by my statement that 610 should never have taken off, and I'm somewhat surprised that it is contentious. I don't care if all the protocols were followed and the logs made (though obviously the pilots of 610 didn't understand what the previous pilots had done to respond to their incident) - in retrospect, we know that the aircraft was not airworthy going into flight 610, so something needs to change so that next time that is detected before takeoff. Whether that is better observation of the protocols or better protocols, I'm not sure.

It's not fixed until it is fixed.

I understand that with physical systems, the cost and complexity of detecting is higher, but if you're putting other people on the line, you damn well better do a live test of your vehicle before another living soul not certified as a pilot or flight engineer is allowed on board.

The more I read about this, the more it appears to me that excessive trust is placed on filed paperwork. Nothing says a fix is done like a successful test flight that specifically attempts to recreate the conditions surrounding the original failure.

Does repaired in this context also include a successful in-flight test?

At some point, the complexity of system integrations requires that you do something more than bare minimum component retesting.

The bathtub curve suggests you shouldn’t. A five year old plane should be safer than a two month old one.

Particularly on a new design variant, there are probably a lot of design/manufacturing issues that can only be found when operated in the field.

Apparently you haven't maintained an airliner.

I think there’s just fatigue with Indonesian airlines’ spaced out attention and not caring about safety over the years, of course the time it’s due to a different reason then no one believes it. It’s the natural consequence of their past record and ignoring warnings.

If there’s a recent case of an airline with a solid track record of following safety recommendations and Boeing not responding appropriately to a crash then that would be different.

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