dmurphynj

Those limits are somewhat living/breathing. I wouldn't be shocked to see another extension as time marches on. It's quite a testament to the 767 to see numbers like that. And United's usage pattern is pretty incredible too --- average of 6 1/2 hour stage length over the history of the frame. For the "baby" wide body, that once served pretty hefty domestic duty, that's pretty amazing. Born in an era surrounded by DC-10s and 747s and L-1011s, into the 777 and 787 era -- that's quite a long stage length.... and some staying power.

Sadly, I agree - this may be DBER. But given the wide body squeeze right now, someone may decide to spend a few million to fix 'er up just to get "over the hump" so to speak. Very hard frame to replace right now - nothing in the desert fits the bill, not manufactured anymore and a sister fleet that's aged but not quite ready for the boneyard.

How quick you think they can get a couple more 777-300ER's out of Boeing?

PsiFighter37

Surprisingly, at least according to my quick Google search, there are still 77Ws being made. I thought UA’s deliveries were basically at the end of the production line, but apparently not!

dmurphynj

There’s 5 left in the order books, but likely to never be delivered.

Wonder if Boeing would entertain building another handful for UA? Would help Boeing bridge the gap till the 777X gets going - as that date keeps slipping, and of course helps United with some much needed capacity.

Understood that they’re not super efficient, but I can’t imagine the per-seat fuel burn would be worse than this bent 763. And if Boeing sold them for the right price …. Well, that’d sure help overcome the fuel costs.

JimInOhio

UA’s 77W has about double the number of seats as some of their 763s (nearly 150 more than on some others). It’s hard to see how a 77W is an appropriate replacement.

dmurphynj

you’re right of course - the 788 would be the closest replacement in the fleet. But I’m sure there’s at least one or two routes that could withstand an upgauge and free up something smaller (like a 788.)

Taken by itself, it probably doesn’t make much sense. But given the overall widebody crunch, I’d guess there’s some shuffling that could be done to reassign frames between routes that are showing large growth.

… then again, I’m not paid as a fleet planner. Which is a good thing — I’m sure my lack of experience would immediately clobber any semblance of airline profits.

ironmanjt

BER-EWR canceled today (8/3) mx

EWR-BER diverted to BOS today (8/3) mx

another 763 supposedly heading to BOS to save those
poor souls now at 1230a.

chances tomorrows EWR/BER goes? It’s currently showing the plane stuck in BOS with mx so I’m expecting a nightmare.

(before anyone calls me out I’m in New York so you can’t blame a connection)

jtet

First, I've been in the loop on a fair number of incident investigations - none involving aircraft. But given my role as a pressure equipment engineer (airline fuselages are, among other things, pressure vessels), I've seen enough jumps to false (even impossible) conclusions written up to know that most folks' "common sense" is not always properly applied, and news reporters are no experts either. So wait until the NTSB report comes out for authoritative conclusions.

On a related note, I'll point out something related to fatigue failure in metals. I work mostly with steel and steel alloys, not aluminum. I'll defer to an aluminum expert if one shows up. Fatigue is a result of cyclic tensile stresses. Determine the three dimensional state of stress to start with. Most engineers will default to simplifying that to a von Mises stress. That's fine for most cases, but for fatigue, you need the first principal stress after you've figured out all three principal stresses. Then you have to look at the difference from the maximum P1 stress in a cycle to the minimum. Have I bored you yet? But all of that evaluation leads to... an idea of where I'd expect a fatigue failure to occur. Such a failure would exhibit itself as a crack initiating and propagating until a tensile (tearing apart) failure becomes apparent. The crack surface will have "beach marks" readily apparent when looked at with a microscope with modest magnification. I'll leave further details to metallurgists. Let me know if any such indicators are found...

Note that I said "tearing" above. That's a completely different failure mode to "buckling". Buckling is caused by local or global structural instability. It is only possible with high absolute value third principal (P3) stresses. Buckling is a function of stiffness, not strength as tensile stresses are. The fuselage can be simplified as a simply supported beam, with the nose landing gear as one support and the main landing gear as the other. Fundamental structural / mechanical statics here. With a load (weight) on such a beam, the beam will bend concave up. By definition, the top of the beam will be in compression, while the bottom will be in tension. Still reading, still following?

Ok so the fuselage in question suffered a significant structural overload. One side - the bottom - was in tension. It didn't exhibit failure that we know of; I've not seen that the bottom of the fuselage tore open. Some version of inspection / non-destructive examination would be required to find small (for now) cracks if any exist. The other side - the top - was in compression. It exhibited wrinkling. A failure mode caused by compressive loads. Not a failure mode commonly associated with fatigue. I'd be hugely surprised if the buckling failure evident in the top of the fuselage had any relationship to cyclic loads.

But as I said... I design and evaluate pressurized cylinders and know nothing about aircraft. I'll leave conclusion drawing to the NTSB and Boeing engineers who have a better understanding of the art than I do.

SPN Lifer

Thank you! It is always rewarding to read something by someone who knows what he is talking about. This is what I appreciate about FlyerTalk.

No, ​​​​nerd, I did not ask my son. While he did indeed take focus sequence courses including aerospace structures, these days he is mostly involved with geotechnical engineering.

itripreport

Looks like it’s not a good week to be flying a 757/767 on both UA and DL… such a shame these birds are now slowly on their last legs.

jhayes_1780

There used to be 6 or so 744's parked in the desert that pmUA just couldn't sell. No idea if they were ever scrapped or current disposition. FAA still shows the certificates as "valid", I know I've seen other status on FAA as "scrapped, sold, exported, transfered etc".

Before I get flamed.... I know there is zero chance this could happen, as if those frames would need heavy checks, and pilot/crew training (just an all around impossible task). But its fun to dream about sitting on the upper deck of a UA 744-422 again, right?

pseudoswede

Wishful thinking, indeed! I thought UA did have some 757s and 767s in storage in Arizona or California. With a bit of Googling, there are a few commercial 767s (and 787-8) for sale right now.

jhayes_1780

IIRC, I *think* (I could be very wrong) but the stored pmUA 752's were sold to fed ex for conversion/parts. Not sure on the 767's.

ironmanjt

Nope....and another bites the dust (at least for another day or so) - N649UA went EWR-BER last night but diverted to BOS...where it's stuck and might get back to EWR late tonight...might... swaps BER to a 767-400 today...

pseudoswede

Forgot about the United Fleet website.

According to that, there are currently 10 752s stored. Many other 752s were indeed sold to FedEx, sold to other parties, returned to leasing companies, or scrapped. All of their 762s were sold or scrapped.

CApreppie

Just caught up on this thread. Pretty bad damage. I'll say this 767 gets parted out and sent on its way to a scrap yard.

Not sure if this has been asked, when trainees bungle up this badly, is this a look for a new job/role situation?