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by privateSFacct 2433 days ago
There record is not dismal with the 737MAX.

If you look at where fault lies part lies with boeing and part lies elsewhere in the safety chain. In contrast to many other areas - the evidence of ill intent is relatively weak here. Even without prison Boeing is facing major financial impacts as a result of this issue (as it should).

It's looking like evidence from the airlines that proper maintenance was done may have been faked.

https://www.bloomberg.com/news/articles/2019-10-15/pictures-...

We know lots of maintenance issues unaddressed and repeated warnings by the plane itself that there were sensor issues were not properly addressed.

We know response was not ideal on pilot side which overlaps with some training and other items around stab trim cutoff and/or automation dependency.

These factors are partly why there have been no accidents in 737MAX in US despite lots of flying.

Yes - boeing should design a totally safe plane. Part of that is going to be designing plans to accommodate a wider range of pilot skill (what they are calling "future pilot populations") and to better accommodate maintenance and ground handling training assumptions to allow for greater risk of problems there. This is already being implemented.

Ironically, one element may be to REDUCE the reliance on pilots as a key flight safety control and then increase automation and redundancy in the automation.

2 comments

> Their record is not dismal with the 737MAX.

By what metric?

By every metric I can find (passenger deaths per trip/flight leg/flight mile, hull losses per delivery/year, etc) the MAX is an outlier.

In fact, I can't find any other airframe in the last 50 years that even comes close (including the DC-9 and TU-154). What other airplane has killed 300+ passengers in its first 4 years of operation?

So, what metric have you selected to show that the MAX isn't dismal?

(and please, no lie-with-statistics stuff like hiding the MAX in 737NG data, or claiming that crashes by foreign pilots or on foreign soil don't count)

> the evidence of ill intent is relatively weak here

Most people are referring to negligence, not ill intent. "Let's make more money and rush this thing out! (Even though this could kill people)", not "Let's deliberately design a system to kill people".

Regardless, one sensor failing should not induce a plane to fly itself into the ground, despite the best efforts of the pilots to recover (and despite the fact they were not necessarily the best trained pilots). 2 / ~400 complete hull losses of brand new jets is completely unacceptable. That is dismal. Don't try to downplay it.

These were not the "best efforts" to recover - stab trim cutout is a memory item.

Absolutely - Boeing is going to be designing much safer planes in future to accommodate different pilot populations. That is clear and necessary. This will make us all safer. Boeing obviously screwed up with a primarily US based mentality.

This system was PARTICULARLY fragile in the face of poor maintenance and reliance on automation - which boeing was unreasonably dependent given a US centric view.

Look into history of comets and concorde if you want to look at hull loss rates (note - both stopped flying forever when safety issues became clear). I predict almost no chance that the max will be taken out of flying forever.

> stab trim cutout is a memory item

1. MCAS does not behave exactly like a normal runaway trim.

2. On the Ethiopian crash, they _did_ initially follow the stab trim cutout procedure, but they didn't manage their speed correctly and thus were unable to control the plane with manual trim.

IMO point 2 is very important - pilots will not always be perfect. It's easy to armchair pilot from your couch and say that "Oh, just manage your speed correctly when your plane is trying to pitch itself into the ground just after takeoff and follow the stab trim cutout procedure. Very easy to deal with MCAS." But reality is not that easy.

> Look into history of comets and concorde if you want to look at hull loss rates

Compared to every other new plane released in the past 20 years, the 737 MAX has a terrible hull loss ratio. I don't really care about the Comet or the Concorde since it's 2019.

Agreed - pilots will not always be perfect, and if the safety chain -> design of systems, maintenance, training, experience is weaker than this will matter more.

Pilot error still #1 cause of fatalities including in the US. In this case bad maintenance also looks to be an issue and a brittle design. You have a master caution on 4 seconds into flight - you've got a terrible maintenance log book etc. I actually thought initial stab trim call wasn't unreasonably delayed - though they did let it run 4.6 to 2.1 over 10 seconds or so, which is a HUGE trim change.

And stab trim cutout wasn't followed fully or MCAS wouldn't have been able to put them into the ground at the end, though they may have already in a bad spot so thinking not unreasonable, except of course you might sit on nose up trim for a bit once reversing cutout.

The move will be I think to more automation and reducing ability to dispatch with things like a flight computer out of service (histrionically pilot skill would cover this now).

I also think they may need to move to authenticated maintenance / self test / parts life / history items. Ie, prevent dispatch on sloppy fixes / sloppy test.

By US-based mentality, you mean one where it's OK to design an automation system that takes input from a single sensor? And this is somehow OK for American pilots, but not for foreigners?

I think evidence will show you're wrong. The MCAS is a terrible design no matter where you intend to fly it.

Yes - automation in the US context has historically evolved with pilots pilots considered a key and reliable redundancy. So yes - the automation is not full automation / full redundancy. The idea has (historically) been then that the pilots bring overall safety to required standard and the pilot is the redundancy. The evidence in the US has showed that this approach works from everything from stab trim cutout issues to dual engine failures.

In the US, efforts in last years have focused on the entire chain of safety (actually away from plane design) and the US has hit some of the BEST periods of safety in aviation. This is everything from duty / rest periods, maintenance, minimum training requirements etc.

"And this is somehow OK for American pilots, but not for foreigners?"

Let's be VERY clear here:

The requirement to fly Part 121 in US even as just a first officer requires an ATP and 1,500 hours. Most folks have a a significant amount of other flying prior to that, the US has a much bigger GA aviation scene, private flight instruction, glider, private jet / charter markets and military flying. The US has something like 12,000 pilots flying for the air force alone. The first officer on your long flight is very very likely to have a TON of experience in all sorts of situations, and particularly with manual flying.

Overseas - you can be a graduate with an academic / training background only and 250 hrs of "flight time" more broadly defined and be at the controls. Ethiopian airline pilots were 25 and 29 years old.

In the US, major carriers even more picky.

Southwest for example:

Flight Experience: 2,500 hours total or 1,500 hours Turbine total. Additionally, a minimum of 1,000 hours in Turbine aircraft as the Pilot in Command* is preferred. Southwest considers only Pilot time in fixed-wing aircraft. This specifically excludes simulator, WSO, RIO, FE, NAV, EWO, etc. "Other Time" will not be considered.

So yes, if boeing is going to sell into markets with folks getting into cockpit as co-pilots with sometimes as low as 50 hrs (1 week) of experience (in cadet / training systems) then 100% they will need to redesign and rethink things for this future pilot population - and yes, that means the systems will have to have MUCH more natural redundancy built in.

Ignoring this difference in background, opportunity and skill will lead to lots more deaths - all preventable if the thinking changes and a better understanding of future pilot populations is developed, and that includes accounting for differences in training and experience.

You hype up reliance on US pilot training, but ignore Boeing's intent to NOT train pilots on MCAS (and especially its differences from existing behavior). Plenty of US pilots have gone on record saying that their US-based MAX-8 training left them unprepared to fly the MAX-8 as it was originally delivered.

In fact, even the Southwest pilots you mention disagree with you: https://www.seattletimes.com/business/boeing-aerospace/in-sc...

You're still trying really hard to blame the pilots and ignore critical and unarguable airframe deficiencies. It hasn't worked yet but maybe if you keep writing lots and lots of words you'll get somewhere.

And despite no training we have what may have been some amazingly good MCAS recoveries within the US during takeoff into things like turbulence triggered MCAS nosedowns - pilots thought their own fault / couldn't understand what was going on but the limited reports in terms of response are great for totally untrained situations. I'm sure pilots were pissed, they should be!

I think you are failing to understand how the chain of safety works. Ideally you have a great design. If you don't then ideally the flaws / weaknesses don't get hit because you have things like good maintenance. If you don't have that then maybe next hope is the pilots. Worst case you then you require instrumentation to help reduce risk of the next tragedy. Etc.

This system has resulted in an incredibly safe mode of transport despite many challenges / crazy tolerances etc.