FAA investigating how counterfeit titanium got into Boeing and Airbus jets

But it's also amazing just how few fatal air crashes there are! I know that the FAA is pretty incredible at their job, but there just aren't that many incidents of planes going down and killing everyone on board - and out of those few bad incidents, having two where everything lined up perfectly feelsl weird!

> determines that the probable cause of this accident … Aircraft Engines. The subsequent catastrophic disintegration of the disk resulted in the liberation of debris in a pattern of distribution and with energy levels that exceeded the level of protection provided by design features of the hydraulic systems that operate the DC-10's flight controls.

Under recommendations:

> Encourage research and development of backup flight control systems ·for newly certificated wide-body airplanes that utilize an alternative source of motive power separate from that source used for the conventional control system. (Class II, Priority Action) (A-90-168)

> Conduct system safety reviews of currently certificated aircraft as a result of the lessons learned from the July 19, 1989, Sioux City, Iowa, DC-10 accident to give all possible consideration to the redundancy of, and protection for, power sources for flight and engine controls. (Class II, Priority Action) (A-90-169)

>Analyze the dispersion pattern, fragment size and energy level of released engine rotating parts from .the July 19, 1989, Sioux City , Iowa, DC-10 accident and include the results of this analysis, and any other peripheral data available, in a revision of AC 20-128 for future aircraft certification. (Class II, Priority Action) (A-90-170)

Etc. So calling this a design issue rather than an inspection issue is quite reasonable. Inspections are guaranteed to eventually fail, the aircraft being 100% dependent on them is a recipe for future disasters.

Let’s say there are two conditions X and Y. Neither sole-X nor lonesome-Y, cause the disaster, but when X+Y happen together, they produce a very negative outcome.

It would seem that both are equally “root” of the cause. But human brain desires to declare one as primary.

In situation where disaster was “human died”, with conditions X=“bullet was shot at the human”, Y=“humans are squishy”, we naturally would lean towards X being the root cause, while Y would be treated as ”that’s just the way it is”.

On the other hand we could construct ”human died” situation with reverse root cause assignment, ie. X=“bullet was shot at human” is taken as a constant, while root cause is Y=“ humans are squishy” (employing some grotesque reader can construct a better one, but something like “The journalist should have followed the process and used a bulletproof vest. It is a war zone after all” seem to work)

“Root case” usually is the smallest and most easily changable part of situation that can prevent disaster.

Though the “ease of change” is not fixed. (“People must follow process” vs “invest milions to change process”)

I just wanted to ramble a bit on the concept of “root cause”. To highlight that on precision-of-terminology-spectrum that spans between mathemathics and astrology, “root cause” falls somewhere in the middle. (probably bit to the right of engineering)

The Boeing documentaries I've seen have all been great. It really shows the issues with the Jack Welch model of business that only cares about short term quarterly profits. My father used to complain that every new CEO at his company would first fire a bunch of people to make stock go up even knowing the long term implications would be disastrous. He used to say you could train a monkey to press a button and do that. In the case of Boeing, they used to have an engineering culture that prized innovation and safety. Now they don't even know how to make planes anymore from scratch. All they seem to be capable of is modifying existing designs that are now practically ancient. In my eyes it's like having to do a 5000 mile car race and using a bunch of NOS at the beginning. You get ahead of everyone and then blow out the engine and everyone ends up getting way ahead (ok, I don't know much about cars). It's just overly short term thinking.

It’s perfectly possible that the FAA has correctly optimized for the constraints they are under and the FAA is not sufficiently effective at delivering its charter.

Certainly wasn’t my intention! I don’t _think_ I said anything in there that was assigning blame to the FAA, merely pointing out that in practice they are no longer actively preventing issues.

I know their overall budget has been decreased and there are sources implying that’s the cause of the failures, but I couldn’t (on my phone, to be fair) find any good source comparing the portion of their budget that went to these programs specifically over time. So I chose to stick to what I could source and mostly let people draw their own conclusions.

For instance, while I have Thoughts(TM) I left it to the reader to take a wild fuckin’ guess which political party controlled the presidency, house, and senate in the years we decided outsourced the regulatory role of the FAA to those they regulate.

You are correct that this is what the article says - testing suggests it is in fact titanium, just maybe not the right treatment.

That would be harder, but one would think that a company making airframes for aviation, in a highly regulated environment/etc, would occasionally send off samples to double check them.

Getting titanium analyzed to a degree you could tell whether it is the right grade/alloy is cheap and fast - I can get it done for <$100 per sample.

Given the cost of what they are producing, how few they produce, and how much they sell them for, and how quickly you can get this kind of thing done, they could test every single lot of titanium they get and neither increase cost, nor slow down production.

This also isn't a case where there are lots of people in the middle - this supplier is the ones machining and producing the final product from titanium alloys.

Also, if you change suppliers, wouldn't you at least test the stuff they give you the first time?

I assume that the documentation asserts something acceptable about the manufacturer testing (accelerated, destructive, what have you). In theory it could assert that the production process was such and such without any information about resulting quality assurance, but that seems improbable.

Why can't those tests be repeated (on samples, obviously)?

That’s how you make sure Honeywell actually made this particular part, that your QA signed off on it, and that this particular one was used for stress tests and thus must never, ever end up in the spare parts bin.

This is accomplished by specifying a separate testing house that you trust for this, if you don't have your own equipment. Many manufacturers don't have a tensile test specimen puller, Charpy impact test machine, fatigue test machine, mass spectrometer, x-ray machine, ultrasound technician, or metallurgical lab technician on staff to verify all this. But what you don't do is blindly trust documentation supplied by the vendor.

Not to say you verify every little aspect of everything documented- at some point it's not economically viable. But everything I've mentioned above is pretty reasonable to do, especially as reliability in the end application becomes more critical.

The analogy didn't just not "really work well", it made zero sense. Like, in the first place a counterfeit of anything has to actually pass for the thing, and haggis most certainly does not pass as a croissant.