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Boeing knew of flaw in part linked to UPS plane crash, NTSB report says

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Re: Boeing knew of flaw in part linked to UPS plane crash, NTSB report says

#181

Post by ultrarunner »

wolvoleo wrote: post #165
jacquesm wrote: post #62

Earlier quoted context omitted.

I think every company operating Boeing aircraft should have reviewed their stance on Boeing directives in light of MCAS and the aftermath by now. If they did not that is a failure of sorts as well.

I think in light of MCAS every company operating Boeing aircraft should have reviewed their stance on operating Boeing aircraft. And the worst thing is I don't think even after mcas things have substantially improved there. I've seen more spin and damage control than actual safety focus. They could have launched a huge company program and management reorganization to really turn this mindset around. I think the bigge…

And what’s more, the FAA is currently moving away from DERs and to ODAs, which is the program that enables Boeing’s flavor of self- oversight

https://avbrief.com/faa-wants-to-phase-out-ders/

Re: Boeing knew of flaw in part linked to UPS plane crash, NTSB report says

#182

Post by robocat »

jacquesm wrote: post #103
potato3732842 wrote: post #101

Earlier quoted context omitted.

>I owned a machine shop, and I'm the founder of a mid sized CNC gear factory. I think I know my way around bearings, lubrication, press fits and other such bits & pieces. Then you have no excuse for having such a nuance free opinion for you must know things are often not obvious at "first glance of pictures someone else took" which is what we're all doing here. >I'm doing the exact opposite of what you claim. I am ju…

> I disagree. You are acting like this is a cut and dry situation wherein the Boeing advice that this was not safety critical is just wrong on it's face. That assessment was made 15yr ago (perhaps by "old good boeing" engineers) and on a part already under a lot of scrutiny from the other MD11 that lost an engine. Sure they could be wrong, but I wouldn't bet on it so confidently. Well, those good old Boeing engineers…

I apologize... My original comment was poorly thought out and naive, which misled potato and you.

You and potato followed that wrong path and unfortunately didn't correct me or yourselves. I tried to correct myself later (see my sibling comment), but I wouldn't be surprised if I've made another huge cockup with the facts.

> Yes, that bearing only moves a few degrees

It certainly does not move a few degrees (except maybe after a crash).

Thinking back to my one undergrad mechanics paper, I think the design purpose was to make torsions equal zero, so that the mechanical analysis would be tractable.

The torsions should still be extremely low because nothing can rotate (except maybe a tiny amount due to deformations).

If we can't get the engineering facts straight, then our opinions on engineering management are likely to be even more pointless and flawed.

You seem to have gone off the rails as much as potato.

The report seems to be implying that the broken bearing is the cause of the accident. The bearing was still in place after the accident so presumably the bolt didn't shear. If the engine has full acceleration then the engine is pitching upwards against the wing and the force on that bearing is upwards?

I think the report implied the fire occurred at the same time as the structural failure.

What might be the chain of events from a broken bearing to a fire?

Re: Boeing knew of flaw in part linked to UPS plane crash, NTSB report says

#183

Post by K0balt »

expedition32 wrote: post #105
K0balt wrote: post #67

Earlier quoted context omitted.

Mmmm…. Not saying us pilots are universally great, but I have definitely seen a significant regression from the mean in many foreign cohorts. I imagine it’s due to fundamental differences in the concept of training. It’s one of the things besides war that fear based societies seem to do better than shame based societies.

Civilian pilots have to consider that they are flying in heavily congested airspace with 200 passengers in the back. They are not LARPING Chuck Yaeger in the right stuff.

Well, not with that attitude, they aren't. But I've been on some charters where I'm pretty sure that they were, in fact, larping Chuck Yeager. I've seen a solid 2.5-2.8G turns in a 737, as well as some cornea-peeling rotations to max climb. It's kinda funny how things sometimes change when the plane isn't full of paying passengers.

I mean, those are pretty standard maneuvers, up to 4gs or so, in small aircraft, and I used to fly aerobatic frequently... but it just hits different somehow on an aircraft that weighs 70 tons and flexes visibly.

Re: Boeing knew of flaw in part linked to UPS plane crash, NTSB report says

#184

Post by metalman »

12_throw_away wrote: post #144

Reading the actual NTSB report [1], my first reaction is just my usual awe at the professionalism of the NTSB. They started with a 3000-ft-long debris field and in the end could say "here are the microscopic stress fractures in the left pylon aft mount bulkhead's wing clevis spherical bearing assembly's ball element's forward bearing race". [1] https://www.ntsb.gov/investigations/Documents/DCA26MA024%20I...

as a pilot, we attend regular training sessions, often hosting senior accident investigators who continue to follow a strict logical method where you start with nothing, zero knowledge, just physical evidence and recordings, eyes, ears, nose, touch, and I bet the sneaky ones are tasting stuff. It's a small community, everyone has lost a friend, knowledge and information is sought and shared in a very particular way when it comes to saftey and reliability, though of course there are cheats and greed, passive agresives comiting crimes of omission. and so, here we are, again.

Re: Boeing knew of flaw in part linked to UPS plane crash, NTSB report says

#185

Post by jacquesm »

tiahura wrote: post #146
12_throw_away wrote: post #144

Reading the actual NTSB report [1], my first reaction is just my usual awe at the professionalism of the NTSB. They started with a 3000-ft-long debris field and in the end could say "here are the microscopic stress fractures in the left pylon aft mount bulkhead's wing clevis spherical bearing assembly's ball element's forward bearing race". [1] https://www.ntsb.gov/investigations/Documents/DCA26MA024%20I...

To be fair, there were a few folks on x avh and the other typical sites who guessed the cause pretty quickly.

If a few thousand people speculate some of them will get it right. It means nothing.

Re: Boeing knew of flaw in part linked to UPS plane crash, NTSB report says

#186

Post by foldr »

ethbr1 wrote: post #180
Someone wrote: post #175

Earlier quoted context omitted.

> They'd have to show at least one plane with a bearing gone that still flies as intended. That depends on the meaning of “safety of flight”. I don’t know what it means in aviation, but do not rule out that there is significant room between “flies as intended” and “result in a safety of flight condition”. For example, if an engine were to complete drop off the plane, would that necessarily result in a safety of fligh…

Some of it may be related to the 3-engine design, if Boeing had modeled that 2 engines still provided sufficient power in all scenarios. But a takeoff does seem like the worst time to catastrophically lose 1/3 power, even without FOD intake by the central engine.

Certainly two engines would provide enough power in all scenarios, including take off. That’s a fundamental safety requirement that any airliner meets.

Re: Boeing knew of flaw in part linked to UPS plane crash, NTSB report says

#187

Post by kayfox »

ksaj wrote: post #166
beowulfey wrote: post #90

Earlier quoted context omitted.

They may have meant grounded, not decommissioned. DC-10s were grounded alongside the MD-11s. https://www.flightglobal.com/safety/us-faa-broadens-md-11-gr...

Close. I meant decommissioned from the UPS fleet, nearly 25 years ago. MD11 was considered a more modern and flexible replacement.

Did UPS Airlines ever fly the DC-10/MD10?

FedEx did and they retired them in the last 5 years because they had reached the end of their economical service lifetime and not because of any major flaw.

Re: Boeing knew of flaw in part linked to UPS plane crash, NTSB report says

#188

Post by kayfox »

ceejayoz wrote: post #79
hshdhdhj4444 wrote: post #69

Earlier quoted context omitted.

Correct. And you could pay for the MCAS to use both sensors which all US airlines did. Edit: I was misremembering. Both sensors were enabled on all planes and MCAS only used one at a time on all planes. What was disabled, unless paid for, was software which displayed to the pilots that the 2 sensors were disagreeing, which would immediately have alerted them to what may have been wrong. > According to Bjorn Fehrm, Ae…

It’s kinda darkly refreshing that purchases in the tens/hundreds of millions of dollars still try to nickel and dime you.

Airlines don't negotiate prices based on the exact options selected, they select a list of options and then negotiate on price from there. This particular option does not appear to have a price associated with it, it just increases the cost of training and documentation for pilots and some airlines would opt out of using it.

People talking about MCAS seem to simultaneously pound the line that everything on the aircraft the pilots encounter should be trained for and forget that adding new stuff to the flight displays will incur additional training that an airline may not want to deal with.

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