UPS MD-11 crash at SDF

Maybe this indicates a need for redundancy in future aircraft designs, so the failure of a single critical component won't send an engine flying off the wing.
 
arkavgal said:
Maybe this indicates a need for redundancy in future aircraft designs, so the failure of a single critical component won't send an engine flying off the wing.
Click to expand...
It's already been implemented. But the truth is that you can't just bolt an engine to an airplane, that's a recipe for disaster. When I'm asked about this by folks with no idea I'll tell them the engines are held on by 3 or 4 1/2" bolts and maybe a trunnion bolt. If they ask more questions I'll explain bushings, spherical bearings, thrust struts, loads and relative motion. If not I don't mind them walking away terrified of flying. I'm not going to convince them of anything, I'm just a dumb mechanic.
 
FlyingAccountant said:
www.flightglobal.com

UPS MD-11F crash hearing details multiple prior pylon bearing failures - FlightGlobal

Fatigue cracking led bearing race to split and put abnormal stress on lugs anchoring pylon to wing. While an investigative hearing has opened to determine the circumstances of the fatal UPS Boeing MD-11F accident at Louisville in November last year, the inquiry has revealed that bearing...
www.flightglobal.com www.flightglobal.com

This doesn't exactly portray Boeing in the best light. It was a known issue since at least 2002. Three of UPS's other MD11s were found to have similar defects.
Click to expand...
I haven’t watched the whole hearing but this is something that stuck out to me. They’re all GE iirc. Even more concerning was two of those airplanes flew after the crash.
 
knot4u said:
It's already been implemented. But the truth is that you can't just bolt an engine to an airplane, that's a recipe for disaster. When I'm asked about this by folks with no idea I'll tell them the engines are held on by 3 or 4 1/2" bolts and maybe a trunnion bolt. If they ask more questions I'll explain bushings, spherical bearings, thrust struts, loads and relative motion. If not I don't mind them walking away terrified of flying. I'm not going to convince them of anything, I'm just a dumb mechanic.
Click to expand...
I'm the same way when I try to explain quantum mechanics to someone
 
Murdoughnut said:
Based on that, it seems more unusual to me that UPS got rid of the fleet. If it's a stress fracture that builds over time, seems like that's something you could inspect regularly, but I speak out of admitted ignorance.
Click to expand...
There’s actually no way to inspect this visually without doing some NDI method, unless maybe they can get a boroscope in the clevis and look for the separated outer ring being pushed out the sides.The part that failed is the outer ring, which is sandwiched between the bearing inner ring (ball) and the two lugs. Making an educated guess, but the fix would be to remove the engine and pylon from the aircraft, press out the spherical bearing from the lugs, inspect the inner bore of the lug (maybe with Eddie current or similar to find cracks), replace with a new spherical bearing with a thicker outer ring, and put the pylon and then engine back on the airplane. (Emphasis on the pylon first since trying to put pylon+engine back on the plane at the same time is what caused the AAL191 crash when this same part failed the last time in 1979.)

It’s very doable but costly which is probably why UPS didn’t do it. The FAA should have made them do it with an AD, not a service bulletin.
 
inigo88 said:
It’s very doable but costly which is probably why UPS didn’t do it. The FAA should have made them do it with an AD, not a service bulletin.
Click to expand...

Agreed. However UPS, in my mind, doesn’t get a pass on this nor do they get to punt it all to Boeing. While an AD would’ve been nice and probably more appropriate, the SB’s subject matter and criticality of the specific item in question, should’ve been taken more seriously by UPS as something that should be complied with and completed without having to specifically be ordered to by Boeing or the FAA. If not for simple safety considerations, much less every other consideration to occur were an accident to occur, like is being seen now. Sure, it would cost some dollars to do, which is always the number one consideration. But compared to what costs they are facing after this accident?

And then, to continue launching MD-11s on missions on the hours and days following the accident before the FAA grounding? That’s mind boggling. I think it was page 4 or 5 of this thread on the day of or after the accident, that I posted that there needs to be a fleet grounding or pause and has it been done.
 
MikeD said:
Agreed. However UPS, in my mind, doesn’t get a pass on this nor do they get to punt it all to Boeing. While an AD would’ve been nice and probably more appropriate, the SB’s subject matter and criticality of the specific item in question, should’ve been taken more seriously by UPS as something that should be complied with and completed without having to specifically be ordered to by Boeing or the FAA. If not for simple safety considerations, much less every other consideration to occur were an accident to occur, like is being seen now. Sure, it would cost some dollars to do, which is always the number one consideration. But compared to what costs they are facing after this accident?

And then, to continue launching MD-11s on missions on the hours and days following the accident before the FAA grounding? That’s mind boggling. I think it was page 4 or 5 of this thread that I posted that there needs to be a fleet grounding or pause and has it been done.
Click to expand...

UPS grounded the jets moments before the FAA grounded them. Out of a abundance of caution, UPS said. Maybe the FAA tipped them off that it would look better if UPS grounded them first. Wouldn't be surprised. If the fix had been an AD, UPS would have done it. UPS maintains their jets to the FAA standard, period. Many examples of this in past history. UPS 1354 and the free software mod to the EGWPS they weren't required to perform and the Part 117 cargo cutout. UPS lets the FAA set their standards. It's the difference between a trucking company with airplanes and an airline with trucks. UPS was a very successful comapny for years with this approach.
 
Last edited:
DE727UPS said:
UPS grounded the jets moments before the FAA grounded them. Out of a abundance of caution, UPS said. Maybe the FAA tipped them off that it would look better if UPS grounded them first. Wouldn't be surprised. If the fix had been an AD, UPS would have done it. UPS maintains their jets to the FAA standard, period. Many examples of this in past history. UPS 1354 and the free software mod to the EGWPS they weren't required to perform and the Part 117 cargo cutout. UPS lets the FAA set their standards. It's the difference between a trucking company with airplanes and an airline with trucks. UPS was a very successful comapny for years with this approach.
Click to expand...

Although compliant with the FAA, that maintenance attitude will lead them to payments of those killed.
So, will it be compliant with the insurance companies.
(who REALLY make the laws)
 
inigo88 said:
There’s actually no way to inspect this visually without doing some NDI method, unless maybe they can get a boroscope in the clevis and look for the separated outer ring being pushed out the sides.The part that failed is the outer ring, which is sandwiched between the bearing inner ring (ball) and the two lugs. Making an educated guess, but the fix would be to remove the engine and pylon from the aircraft, press out the spherical bearing from the lugs, inspect the inner bore of the lug (maybe with Eddie current or similar to find cracks), replace with a new spherical bearing with a thicker outer ring, and put the pylon and then engine back on the airplane. (Emphasis on the pylon first since trying to put pylon+engine back on the plane at the same time is what caused the AAL191 crash when this same part failed the last time in 1979.)

It’s very doable but costly which is probably why UPS didn’t do it. The FAA should have made them do it with an AD, not a service bulletin.
Click to expand...
IMG_0484.jpeg

My take away from this slide and my understanding before the hearing was that FedEx has been accomplishing those inspections since the service letter came out in 2008. Clearly there was a way to do it and all it took was the will to accomplish the inspections.
 
It was also telling when they discussed in the hearing that there were 4 examples of separated and migrated outer sleeves on 3 MD11’s and one 10 in the post crash fleet inspections with all 3 of those 11’s being UPS birds. UPS chose to not follow the service letter where others did and that’s very unfortunate.
 
inigo88 said:
There’s actually no way to inspect this visually without doing some NDI method, unless maybe they can get a boroscope in the clevis and look for the separated outer ring being pushed out the sides.The part that failed is the outer ring, which is sandwiched between the bearing inner ring (ball) and the two lugs. Making an educated guess, but the fix would be to remove the engine and pylon from the aircraft, press out the spherical bearing from the lugs, inspect the inner bore of the lug (maybe with Eddie current or similar to find cracks), replace with a new spherical bearing with a thicker outer ring, and put the pylon and then engine back on the airplane. (Emphasis on the pylon first since trying to put pylon+engine back on the plane at the same time is what caused the AAL191 crash when this same part failed the last time in 1979.)

It’s very doable but costly which is probably why UPS didn’t do it. The FAA should have made them do it with an AD, not a service bulletin.
Click to expand...

We really don’t want to know how the sausage is made. So many AD’s just call for inspections, replacements, and reduced TBO’s without really understanding the nature of the problems. Science can be surprisingly weak, small sample populations, lots of assumptions.

Beyond that, AD’s themselves can be an issue as AP’s work outside their comfort zones to comply. This is why some AD’s have lengthy periods for resolution, they don’t want rushed work.
 
Brian29 said:
View attachment 89697
My take away from this slide and my understanding before the hearing was that FedEx has been accomplishing those inspections since the service letter came out in 2008. Clearly there was a way to do it and all it took was the will to accomplish the inspections.
Click to expand...
It's great that FedEx took things seriously and regularly inspected for this problem. But the problem parts identified and fixed by FedEx, weren't they at risk of catastrophic failure? Makes me wonder if the inspections need to be more frequent.
 
arkavgal said:
It's great that FedEx took things seriously and regularly inspected for this problem. But the problem parts identified and fixed by FedEx, weren't they at risk of catastrophic failure? Makes me wonder if the inspections need to be more frequent.
Click to expand...
Great news. The part has been redesigned again and inspection intervals have been reduced.
 
WacoFan said:
How long are you locked in to whatever you have to fly now? When can you bid it again?
Click to expand...
No lock but probably isn’t going to happen. With it supposedly only flying domestic going forward the number of pilots per airplane will be so much less that it will be the most senior airplane. So the ship has sailed, light twin life until the coal mine closes.
 
mightynimbus said:
In other news, 10-Tanker 910/912/914 have all flown recently,
I think 912 might be close to or just carded in last couple days.
It will be good to have them back in the mix for the season.
Click to expand...

Looks like 910 is dropping on Quartz fire by KWMC,
912 shows AV so back in business with at least 2
Glad for them
 
You must log in or register to reply here.
Back
Top