Can anyone explain to a engineering novice what needs to be done to repair this structural damage? I guess it's not done with a bit of using a hammer and some paint.
Would be really interesting to understand what work needs to be performed to ensure a safe operation for years to come. Thanks in advance.

glideslope wrote:

wjcandee wrote:

AMC has to feel just great that Atlas was training the pilot on a live segment with troops on board. Thrilled, I'm sure. Wouldn't a cargo 767 flight have been a better training platform? no wind. 25 mile visibility. Bent plane.

Could not agree more. I was not impressed with the fact it was filled with PAX.

Well you better not being flying with DL, UA or AA along with most if not all of the worlds leading airlines as that's how it's done.

BravoOne wrote:

glideslope wrote:

wjcandee wrote:

AMC has to feel just great that Atlas was training the pilot on a live segment with troops on board. Thrilled, I'm sure. Wouldn't a cargo 767 flight have been a better training platform? no wind. 25 mile visibility. Bent plane.

Could not agree more. I was not impressed with the fact it was filled with PAX.

Well you better not being flying with DL, UA or AA along with most if not all of the worlds leading airlines as that's how it's done.

Thank you for the information. Really don't fly commercial all that much. Just irritated me a bit more that is was an AMC hop.

Perusing Facebook comments I found the following, looks like it will be repaired:

"Shaun Layton So an update on that plane. I towed it to our cargo ramp on Saturday afternoon. Atlas and Boeing plan on fixing it, they are shooting for 2 to 3 months of maintenance to rebuild it. So all you folks who don’t believe me about this, anytime you land at KPSM, just look for the plane with the scaffolding around it near taxi way Mike, you’ll see it as you taxi to the pease greeters area. Now about the center fuel tank there was no damage to it, it didnt leak, we had no spill to clean up, when they strip the plane down more maybe they will see damage to it or not, im not the mechanic, also, unless if i want to keep my job, I won’t be posting pics."

JWKIII wrote:

Can anyone explain to a engineering novice what needs to be done to repair this structural damage? I guess it's not done with a bit of using a hammer and some paint.
Would be really interesting to understand what work needs to be performed to ensure a safe operation for years to come. Thanks in advance.

The airplane will be put on jacks and shored up. Engines removed. The damaged skin, frames and stringers will be removed and replaced or sections spliced in.



Here is a good video showing what sheet metal repair is like:

http://www.youtube.com/watch?v=hv8lmXowrlk

nikeherc wrote:

During certification testing, Douglas broke the rear end off of a super 80. The plane was intended for SAS, but they wanted one that hadn’t been bent. Douglas kept it as an R&D frame after it was repaired.

Eastern and Delta both had DC-9-30's that broke apart along the rear of the wing center section from hard landings. Not bent, broke with the tail section contacting the runways.

nikeherc wrote:

During certification testing, Douglas broke the rear end off of a super 80. The plane was intended for SAS, but they wanted one that hadn’t been bent. Douglas kept it as an R&D frame after it was repaired.

Eastern and Delta both had DC-9-30's that broke apart along the rear of the wing center section from hard landings. Not bent, broke with the tail section contacting the runways.
Sorry. It duplicated my post.

DL_Mech wrote:

JWKIII wrote:

Can anyone explain to a engineering novice what needs to be done to repair this structural damage? I guess it's not done with a bit of using a hammer and some paint.
Would be really interesting to understand what work needs to be performed to ensure a safe operation for years to come. Thanks in advance.

The airplane will be put on jacks and shored up. Engines removed. The damaged skin, frames and stringers will be removed and replaced or sections spliced in.



Here is a good video showing what sheet metal repair is like:

http://www.youtube.com/watch?v=hv8lmXowrlk

Cool, thanks a lot! Very interesting and impressive to see that such a damage can be repaired without having to replace major parts (meaning entire cabin sections) of the aircraft!

A bit more of a repair question:
Are we talking about repair of permanent deformation or just a buckle? Is there some shape-restoration shape involved with the damage like that?

rbavfan wrote:

nikeherc wrote:

During certification testing, Douglas broke the rear end off of a super 80. The plane was intended for SAS, but they wanted one that hadn’t been bent. Douglas kept it as an R&D frame after it was repaired.

Eastern and Delta both had DC-9-30's that broke apart along the rear of the wing center section from hard landings. Not bent, broke with the tail section contacting the runways.
Sorry. It duplicated my post.

IIMN, both ended their careers at NW. Both flew for decades after, though they were 300-400 lbs heavier than other DC9s. (the DL one used a band around the fuselage as a splice plate for the two pieces.

JWKIII wrote:

Can anyone explain to a engineering novice what needs to be done to repair this structural damage? I guess it's not done with a bit of using a hammer and some paint.
Would be really interesting to understand what work needs to be performed to ensure a safe operation for years to come. Thanks in advance.

1. strip out all the interiors and systems from the damaged area both above and below the waterline
2. stabilize the a/c with body and wing jacks
3 place cradles under the damaged section
4. remove the skins and damaged stringers They will probably leave the stringers attached to the skins for removal and cut them off leaving about 8 inches sticking out for splicing the new stringer sections.
5 check for damaged ribs and remove and that are damaged (they may choose to remove all anyway so standard sized fasteners can be used)
6. straighten the fuselage by jacking up the bent section until the waterline is level
7. check for lateral distortion and and correct by moving the cradles
8 when all is square
9 install new ribs
10 install new stringers
11 install new skins
12 if the window band was damaged, they will have some concerns and the window band is probably no longer available new..and cannibalizing one would require testing. With out windows, the plane will probably become a freighter.
13 install all the interior clips, spray with Dinol, electrical harnesses, cabin fittings and interiors.. becoming a freighter will simplify that.
14 pass company, FAA and customer inspection.

kanban wrote:

JWKIII wrote:

Can anyone explain to a engineering novice what needs to be done to repair this structural damage? I guess it's not done with a bit of using a hammer and some paint.
Would be really interesting to understand what work needs to be performed to ensure a safe operation for years to come. Thanks in advance.

1. strip out all the interiors and systems from the damaged area both above and below the waterline
2. stabilize the a/c with body and wing jacks
3 place cradles under the damaged section
4. remove the skins and damaged stringers They will probably leave the stringers attached to the skins for removal and cut them off leaving about 8 inches sticking out for splicing the new stringer sections.
5 check for damaged ribs and remove and that are damaged (they may choose to remove all anyway so standard sized fasteners can be used)
6. straighten the fuselage by jacking up the bent section until the waterline is level
7. check for lateral distortion and and correct by moving the cradles
8 when all is square
9 install new ribs
10 install new stringers
11 install new skins
12 if the window band was damaged, they will have some concerns and the window band is probably no longer available new..and cannibalizing one would require testing. With out windows, the plane will probably become a freighter.
13 install all the interior clips, spray with Dinol, electrical harnesses, cabin fittings and interiors.. becoming a freighter will simplify that.
14 pass company, FAA and customer inspection.

Interesting and informative but ‘waterline ?’

Crosswind wrote:

The 767 has a particular weakness in this area


Vietnam Airlines 2000
https://aviation-safety.net/database/record.php?id=20000919-0

Thomson Airways 2010
https://aviation-safety.net/database/record.php?id=20101003-0

Best Regards
CROSSWIND

Crosswind, thanks for compiling the list. It's interesting to note that the Vietnam Airlines incident and the Thomson incident are the same aircraft... the UK accident report has photos of the damage the plane received in both the 2010 and 2000 incident.

Max Q wrote:

Interesting and informative but ‘waterline ?’

this should help https://aviation.stackexchange.com/ques ... n-aircraft

although I should have said the floor is level

kanban wrote:

Max Q wrote:

Interesting and informative but ‘waterline ?’

this should help https://aviation.stackexchange.com/ques ... n-aircraft

although I should have said the floor is level

Thanks KB, interesting and a new one
on me

kanban wrote:

JWKIII wrote:

Can anyone explain to a engineering novice what needs to be done to repair this structural damage? I guess it's not done with a bit of using a hammer and some paint.
Would be really interesting to understand what work needs to be performed to ensure a safe operation for years to come. Thanks in advance.

1. strip out all the interiors and systems from the damaged area both above and below the waterline
2. stabilize the a/c with body and wing jacks
3 place cradles under the damaged section
4. remove the skins and damaged stringers They will probably leave the stringers attached to the skins for removal and cut them off leaving about 8 inches sticking out for splicing the new stringer sections.
5 check for damaged ribs and remove and that are damaged (they may choose to remove all anyway so standard sized fasteners can be used)
6. straighten the fuselage by jacking up the bent section until the waterline is level
7. check for lateral distortion and and correct by moving the cradles
8 when all is square
9 install new ribs
10 install new stringers
11 install new skins
12 if the window band was damaged, they will have some concerns and the window band is probably no longer available new..and cannibalizing one would require testing. With out windows, the plane will probably become a freighter.
13 install all the interior clips, spray with Dinol, electrical harnesses, cabin fittings and interiors.. becoming a freighter will simplify that.
14 pass company, FAA and customer inspection.

Thanks Kanban for the detailed explanation. I guess straightening a Boeing 767 is a complicated job, what are the margins of error here? Less than a millimeter?
Great feedback from the Forum, though! Thanks a lot.

More or less.. remember on a plane this size the dreaded 'accumulation of tolerances' also plays a role.. i.e all drawing measurements are +or- X usually 0.01 inches so if all the tolerances were on the plus side the plane will be longer than ones where some tolerances are on the minus side.. when repairing an aircraft generally the do not use pre drilled parts because of this

When this happened to CN-RNT at JFK Airport (it wasn't noticed until the next crew's pilot was doing a pre-flight check), which involved a crack close to where it happened here on N641GT, that aircraft was grounded for nearly 4 months. I would be looking at around US Thanksgiving Day for a return to service. The difference is that this aircraft is 26 years old, while CN-RNT at the time of its incident was 7 years old (and leased; N641GT is owned by Atlas Air outright). I have to wonder what factored into the decision to repair a 26-year old 767 with almost 84,000 hours on it.

aemoreira1981 wrote:

When this happened to CN-RNT at JFK Airport (it wasn't noticed until the next crew's pilot was doing a pre-flight check), which involved a crack close to where it happened here on N641GT, that aircraft was grounded for nearly 4 months. I would be looking at around US Thanksgiving Day for a return to service. The difference is that this aircraft is 26 years old, while CN-RNT at the time of its incident was 7 years old (and leased; N641GT is owned by Atlas Air outright). I have to wonder what factored into the decision to repair a 26-year old 767 with almost 84,000 hours on it.

I don't think the decision has been made.. the survey by the company, insurance and a repair contractor probably hasn't even started yet. The results and a final decision are probably a month away..

Anyone heard of any updates on her? Will she fly again?

I get a kick out of everyone saying how hard the 767 must be to land. From personal experience, it is perhaps the easiest plane to land I’ve ever had the privilege of flying. Even if this Captain upgraded from a CRJ. I flew that too. Tha is harder to land than the 767.

Sometimes, bad landings just happen. But, in this case, I doubt whether if the Captain flew a 737 beforehand, as some have suggested, would it have been much different.

I just came across this thread on Google and just thought I'd share an update for those interested. The repairs were done by Boeing technicians in VQQ and supposedly cost $8 mil. The following pictures were posted by a couple of our pilots in a closed FB group.

https://imgur.com/a/tDjk16H

FlyGuy747 wrote:

The repairs were done by Boeing technicians in VQQ and supposedly cost $8 mil.

Shows what kind of demand there is right now for 767-300ERs with remaining life. $8M for repairs is easier and cheaper than sourcing another one that's not used to death. This ship is an early build (1992) but has "only" ~25k cycles and ~84k hours, meaning that there are quite some years of flying left at Atlas utilization rates.

Interesting to see the beam through the cockpit glass!

Can anyone describe how the fuselage reinforcement works? Is it bolted on or welded? This kind of stuff fascinates me.

BHM wrote:

Can anyone describe how the fuselage reinforcement works? Is it bolted on or welded? This kind of stuff fascinates me.

Fasteners are used. Airplanes fuselages are not typically welded. Welding reduces the strength of the aluminum.

Welding is used on smaller components,

Didn't Gordon Bethune damage a brand new Continental 767-400 on landing during a delivery flight?

INFINITI329 wrote:

777PHX wrote:

wjcandee wrote:

AMC has to feel just great that Atlas was training the pilot on a live segment with troops on board. Thrilled, I'm sure. Wouldn't a cargo 767 flight have been a better training platform? no wind. 25 mile visibility. Bent plane.

You realize that *no one* flies around empty airliners for operating experience, yeah?

I believe, EASA requires a few takeoffs and landings in the actual airplane before a type is awarded with no passengers. The FAA doesn't but its something I won't be surprised if studied in the future.

Here's Swiss training new pilots on their A330
https://www.youtube.com/watch?v=smmhJ-j8nEI

Depends on previous experience.

True for a 200 hour student straight out of flight training.

Not required for an ATPL holder (>1500 hours)

My first 737, 320 and 330 landings in EASA land were on commercial flights with passengers.

wjcandee wrote:

AMC has to feel just great that Atlas was training the pilot on a live segment with troops on board. Thrilled, I'm sure. Wouldn't a cargo 767 flight have been a better training platform? no wind. 25 mile visibility. Bent plane.

And how do line pilots get their OE done at airlines using that logic?

BHM wrote:

Can anyone describe how the fuselage reinforcement works? Is it bolted on or welded? This kind of stuff fascinates me.

The damaged area is cutout. New structure is installed in place using the same rivet and hilock system the plane is built with. So for a stringer section you fab a new stringer section from the same raw stock as the original. A U shaped splice is fabricated for each end that is very similar to the factory splices. The repair is riveted in place.

Next a new skin section is fabricated to replace the cut out section. Skin splice repairs are fabricated to span the joint to the original undamaged skin. Usually these are on the inside of the plane. It all gets riveted in place just like the original skin was. This same process was used at the factory for joints between skin sections.

Th entire process requires a lot of drilling. This job likely had thousands of fasteners that had to be drilled for installation. Rivet spacing in stringers is typically every inch. The splices are usually every .50-.75 with three to four rows on either side of the skin joint. All this work is done according to the plan the engineering team came up with after they did all their witchcraft math stuff.

If you look at the repair pics, the first pic shows a temporary repair they did to ferry the airplane to the repair facility. They rolled a piece of metal to fit over the damaged skin and then used stringer raw stock the span the damage area. This was all riveted through the damaged stingers on the inside. You will notice the final repair is much bigger. Likely done to avoid the splice repairs for the stringers and the skin to be in the same area.

nikeherc wrote:

During certification testing, Douglas broke the rear end off of a super 80. The plane was intended for SAS, but they wanted one that hadn’t been bent. Douglas kept it as an R&D frame after it was repaired.

The mentioned aircraft was intended for Swissair, not SAS.

Regards