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FAA faces dilemma over 737 Max wiring flaw that Boeing missed

116 points| rbanffy | 6 years ago |seattletimes.com

117 comments

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[+] ChuckMcM|6 years ago|reply
Such are the externalities of taking the opinion "It isn't illegal if you don't get caught."[1] It is interesting that had Boeing not pushed the edge on the re-training re-classification rules they would not have had the crashes, nor the spotlight on them, nor this "new" problem.

As a result I have no empathy for managers who are not getting their bonuses this year, or executives who get fired, or corporations who have to take loans on unfavorable terms in order to weather the storm of consequences brought on by trying to avoid following the rules and incurring the expense such rules incur in their execution.

I do feel bad for the engineers who were fired or moved out of the company by pointing out that management wasn't following the rules. I do feel badly for the employees whose livelihood depends on their working on building these amazing machines being put out of work because the consequences are playing out. And I feel a little bit bad for the airlines suffering from carrying a bunch of planes they can't fly. Hopefully people are learning life lessons in this process and the pendulum will swing back into a safer mode of rule following from the current risk taking behavior.

[1] This philosophy, sadly way too common in my opinion, is that "rules" are for idiots, and since we're not idiots we need only concern ourselves with the risks as we understand them of why the rule should be followed, and ignore said rules when we believe we have no risk of both getting caught nor having the "bad thing" the rule prevents happening (at least on our watch while it would reflect on us.).

[+] inamberclad|6 years ago|reply
They've grandfathered other parts of the aircraft design that aren't nearly as controversial, so Boeing's argument, while predictable, has a little more merit than it seems at first.
[+] maxerickson|6 years ago|reply
The normalization of deviance is a less cynical explanation (in the sense that it doesn't require the process to involve analysis of the risk of getting caught).
[+] Zenbit_UX|6 years ago|reply
> It isn't illegal if you don't get caught.

Illegal seems like the wrong word for this sentiment as it's legal status does not depend on being caught. If I were to rob a bank, it would be an illegal act whether or not I'm caught.

Problem seems like an apt substitute.

[+] rootusrootus|6 years ago|reply
For once, I think Boeing does have a point here. This is the same wiring used on the 737NG, which AFAIK is considered the safest (or one of the safest, at least) airliner ever. The point about rerouting existing wiring introducing it's own potential hazard also seems like an entirely reasonable consideration.

I know it's automatic that we assume Boeing is either nefarious or retarded in everything they do, but it's hard to see this as that big a deal when considering the bigger picture.

[+] kunai|6 years ago|reply
Not to be pedantic but I believe the Airbus A340 is actually regarded as the safest airliner ever, with zero fatalities over the course of its nearly 30-year operational history.
[+] bsder|6 years ago|reply
These rules existed at the time Boeing built and designed this plane, no? And thus the plane was subject to these rules and Boeing never attempted to file for an exemption, correct?

Tough--they should have to rewire the plane.

They cut the corner (or missed the corner) and got caught. Too bad, so sad. Maybe fire a bunch of executives this time and I might have some more sympathy later.

> For once, I think Boeing does have a point here. This is the same wiring used on the 737NG, which AFAIK is considered the safest (or one of the safest, at least) airliner ever. The point about rerouting existing wiring introducing it's own potential hazard also seems like an entirely reasonable consideration.

"Nothing happened before" does not obviate the analysis that caused the rule to be created.

Aerospace rules are generally written in blood. Ignoring them tends to spill more blood.

This is exactly the kind of issue where your reputation is crucial. If your reputation is sterling, then nobody would blink about cutting you slack in this single instance. If, however, your reputation is such that there are likely even more instances like this that haven't been found, then you should get held to the letter of the law.

[+] ilaksh|6 years ago|reply
It is strange to me that this article doesn't question the idea that Boeing and the FAA did not know before that the old wiring didn't meet current standards.

Of course they knew.

But it also seems that the old wiring design has been verified by the test of time and they have data showing the crashes weren't related to it.

So I think that ripping out all of the wiring on the planes and rushing to replace it with a new system, then rushing to test that new system, is the surest way to increase the likelihood of another system failure and possibly even kill off the Boeing brand if that happens.

[+] alkonaut|6 years ago|reply
Put it another way: do I rather fly with the wiring that was tested for 200M hours in the NG, or do I want the configuration that is retrofitted in a hurry to meet the standard? It’s not obvious that trying to “fix” this defect is a good idea.
[+] fooey|6 years ago|reply
If they can't retrofit it in a way that's safe, then to the scrapyard it goes.

All they did was ensure their fix gets even more scrutiny and to require additional proof that it's safe.

[+] rbanffy|6 years ago|reply
I'll just take the A320 instead.
[+] noncoml|6 years ago|reply
False dilemma.
[+] generatorguy|6 years ago|reply
I’m seriously impressed that the distance between the source conductor, command conductors, and presumably return conductors is considered.

As a power systems and controls engineer we make Some effort to separate wires carrying different voltages eg 24v and 480v, but positive and negative run in the same cables or conductors in the same raceway all the time with nary a second thought.

[+] kds3|6 years ago|reply
Those distances haven't been considered until real electrical shorts happened, safety standards are written in blood:

> The regulation was introduced in 2009 following study of two fatal crashes: TWA 800 in 1996, in which an electrical short is believed to have caused a spark in the fuel tank and an explosion; and Swissair 111 in 1998, when an electrical short caused a fire in the cockpit.

[+] myself248|6 years ago|reply
The FAA and its sister agencies around the globe are very good at root-cause analysis. Where a single fault could cost many lives, there's strong incentive to follow any failure all the way back.

I'm guessing that your systems don't experience anything like airplane levels of vibration, or have anything like airplane numbers of fatalities if the controls fail, yeah?

[+] disillusioned|6 years ago|reply
Is there something to be said or considered for the fact that the wires are in a dynamic system that might vibrate or chafe away insulation? I feel like that's a big part of the consideration in the separation criteria here, but I'm not an aviation or electrical expert at all.
[+] pdonis|6 years ago|reply
Since the wiring standard under discussion here was only introduced in 2009, an obvious question is: how many other aircraft models currently in service, besides the 737 (and not just the MAX), have a similar issue that has not been caught simply because no updated analysis of their certification was done after 2009?
[+] jojo2000|6 years ago|reply
> “There are 205 million flight hours in the 737 fleet with this wiring type,” a Boeing official said. “There have been 16 failures in service, none of which were applicable to this scenario. We’ve had no hot shorts.”

This is appalling as this company exhibits the same excuses as before "there was no problem yet". Persistence in unfit behaviour at its best.

[+] pdonis|6 years ago|reply
> This is appalling as this company exhibits the same excuses as before "there was no problem yet".

Saying "there was no problem yet" about something that's only been in service for a relatively short time, yes.

Saying "there was no problem yet" about something that has been in service since the 1960s, not so much. If the FAA were to force Boeing to change this wiring on the 737 MAX, to be consistent, they would also have to change it on every single 737 of every model that is still in service--including many airplanes that have been in service for decades with no problem.

That's a very different argument from "the FAA skimped on the MAX before, so we shouldn't let them skimp on it again".

[+] inamberclad|6 years ago|reply
You'd be horrified to learn that every country in the world certifies aircraft based on estimated failure rates per flight hour per component then.
[+] raverbashing|6 years ago|reply
No failures after 205Mi flight hours is not an excuse, it's a statement.

In fact, similar statements are valued in the aeronautical industry (engine failure rates, etc).

The Max failed much earlier than those 200Mi hours.

[+] cmurf|6 years ago|reply
potential for an electrical short to move the jet’s horizontal tail uncommanded

I think this is a reference to the stabilizer, because the elevators are controlled by cable connected to the yoke and are hydraulically powered. Since stabilizer (trim) can overpower elevator force, uncommanded changes in this control surface could be really bad, depending on how a short manifests into control surface movements.

I can't assess the relative probabilities: a short happening vs the fix inducing some other problem. But I do wonder whether there's another way to mitigate it.

[+] Gwypaas|6 years ago|reply
Today it's mitigated by the pilot. Runaway Stabilizer is a memory-item. [1]

This is the same memory item Boeing thought would mitigate MCAS, since that is essentially a runaway stabilizer trim, although in retrospect behaving in a very different manner making it much harder to diagnose.

[1]: http://www.b737.org.uk/runawaystab.htm

[+] LorenPechtel|6 years ago|reply
Since Boeing has taken the path of seeing what they can get away with the only appropriate response from the regulators is not to allow them the slightest deviation.

If the 737 Maxes can't be adequately fixed then send them back, refund the purchase price.

[+] pdonis|6 years ago|reply
It's not enough to just regulate this on the 737 MAX. This wiring is the same on every single 737, of any model, that is in service. That includes airplanes that have been flying for decades with no incidents. Do you want to ground them all?
[+] tinus_hn|6 years ago|reply
I’m not sure what the dilemma is here. They made the rules, should they apply them or not?
[+] einpoklum|6 years ago|reply
The rules are based on certain models of assessing chances of malfunctions like shorts.

Boeing is claiming that the service time of their wiring setup is sufficient evidence to justify an exception to applying the harsher model.

It is not an incredulous claim, and not a trivial dilemma.

[+] kube-system|6 years ago|reply
The repair or modification of wiring harnesses is often a risky repair.

I'm not an aerospace expert, but I know that even major automakers usually won't allow their dealers to do repairs to wiring harnesses because it poses too much risk.

[+] ggambetta|6 years ago|reply
I think the dilemma is "but money". I agree, the situation is ridiculous.
[+] tobbykop|6 years ago|reply
It sounds like the dilemma might be that facts support not pushing for a repair, but if they go with that they’ll be butchered by the media and the masses.
[+] redis_mlc|6 years ago|reply
There's a lot of misunderstandings in the comments here.

When you're dealing with complex wiring harnesses and wiring runs, there are always problems. For example, the A380 and one of Boeing's new airliners were delayed because stuffing the wiring harness in the nose didn't work.

In the case of airplanes, things flex and bend, causing wire chafing.

So there's no black and white answer to, "Is the wiring perfect?"

The only good solutions are:

1) When new airplanes are made, improve the wire layout

2) When old airplanes get a heavy maintenance check (D-check), possibly inspect and redo the wiring then.

3) Consider using conduit for safety-critical runs. Makes it harder to inspect, though. :)

Anyway, the Swissair 111 fire/crash was because of new gambling screens igniting flammable materials. Sure that was an electrical fire, but from adding entertainment equipment.

Swissair 111: "flammable material used in the aircraft's structure"

https://en.wikipedia.org/wiki/Swissair_Flight_111

Source: commercially-rated pilot

[+] hurricanetc|6 years ago|reply
Boeing is right but the FAA can’t afford to give them a waiver because reciprocity agreements might go up in flames.

Boeing will pay twice because their incompetence highlighted the incompetence of the FAA.

Not that I particularly care. I hope Boeing goes bankrupt.

[+] product50|6 years ago|reply
Whenever it is approved, 737 MAX is likely going to be the safest aircraft that Boeing would have produced. There has been so much scrutiny after the past 2 crashes that at this point every remote possibility has likely been considered and taken care of.
[+] Waterluvian|6 years ago|reply
Articles like this speak as of thr FAA has the sole authority to bring the Max back into service.

Doesn't it require other agencies in Europe and China to do the same? How useful is a fleet that can't fly in large segments of the world?

[+] echelon|6 years ago|reply
I don't know what the point of salvaging this plane is at this point. I'm never going to get on board one of them.

Could they convert the entire fleet into cargo jets, or does the configuration not match that role?

[+] MertsA|6 years ago|reply
What about this is something that's too complicated to retrofit? Why would they even need to tear into existing wiring harnesses to fix this? Just run another wire through the new pathway isolated from everything else and decommission the old circuit by cutting the ends of the wire and slapping a heat shrink cap over them. Sure, fix the harness on new planes but is there really too much red tape to come up with a safe retrofit plan that doesn't involve messing with the existing harness?
[+] vardump|6 years ago|reply
I think the main dilemma could be a bit different.

It's true that the wiring harness is already proven with 737 NG. And it's probably true rewiring 737 MAX is a higher risk than doing nothing.

But IF this issue causes an accident without attempt to fix it, Boeing as a company might never recover. Even one such case could be enough.

So both not doing anything and fixing it carry a huge risk. Not fun to be Boeing these days...

[+] doggydogs94|6 years ago|reply
I suppose Boeing could just cancel the whole 737 series and file for Chapter 11.
[+] catalogia|6 years ago|reply
A reorganization is possible but I really doubt the American government would allow Boeing to be truly imperiled. The US Military has thousands of Boeing aircraft, particularly all of the large tanker jets used for aerial refueling are made by or supported by Boeing (some were made by McDonnell Douglas, before Boeing bought them.) Some of America's military aircraft are even derived from the 737.
[+] craftinator|6 years ago|reply
Glad Boeing isn't in charge of anything important.
[+] ricw|6 years ago|reply
The situation is pretty clear. They need to fix the wiring issue. Stick to the regulation or don't regulate...

It's also shocking to me that the MAX may be rectified when depending only on one angle-of-attack sensor (the one that caused the two prior crashes). They should mandate that at minimum 2 redundant sensor must exist, at minimum. Really it should be 3 sensors for flight critical input, as has been the case for all modern airplanes.

[+] pdonis|6 years ago|reply
> They need to fix the wiring issue. Stick to the regulation or don't regulate...

Fixing the wiring issue would mean fixing it on every single 737 in service, not just the 737 MAX. Many of those airplanes have been flying for decades with no incidents. Tearing them apart to rewire them might make things worse overall, not better, since any repair always has the risk of introducing some other problem.

[+] FriendlyNormie|6 years ago|reply
These sensors cannot possibly be expensive to build. Why aren’t there one hundred sensors on each plane? Trust whatever the majority of sensors report, notify that outliers need to be serviced.
[+] mnm1|6 years ago|reply
Expecting Boeing to regulate itself is like expecting a dog to not eat from its bowl when hungry. It ignores basic human nature and the incentives companies have to make profits at any costs, even if those costs are hundreds of human lives. I'm sure there are plenty of other things overlooked on this plane and others since the FAA gave up their oversight duties, their major reason for existence. When a company like this is unaccountable to anyone, we've seen what happens, yet there is still a question as to whether regulations should be enforced? How many more people need to die needlessly before the government steps in and does its job?