Omni 767 gear collapse in Bucharest

[Check Airman]

Accident: Omni B763 at Bucharest on Aug 28th 2020, left main gear collapse on landing (http://avherald.com/h?article=4dbdfa02&opt=0)

[White Knight]

After the FedEx 767 incident in LA the other day it's looking like it's time to retire these venerable old ladies!

[Flightmech]

What? They’re still rolling off the line today and the FedEx jet was only just over three years old?

[White Knight]

Guess I don't keep up with what's happening at Boeing:}

Out of interest then, how old is the Omni 'frame involved in this incident?

[733driver]

Took me 5 seconds to google the registration from the link in the first post. It's 24 years old.

[Rt Hon Jim Hacker MP]

At 24 years old the gear will most likely have been changed twice.

[White Knight]

733driver

Excellent! I'm having a lazy day:ok: But thanks:)

[tdracer]

24 years old isn't particularly high for a 767. I didn't find anything on hours/cycles when I Googled (and I've not had access to the Boeing data base since I retired), but there are a fair number of 767s still in service with north of 100,000 hrs, still going strong without the gear collapsing.
As Hon Jim alludes to, a gear collapse is most likely faulty maintenance.

[Spooky 2]

As I recall when referencing the Boeing Low Utilization Plan a gear overhaul something like 10,000 landings, or 10 years which ever came first.

[Klimax]

Prob some cheap short cut maintenance done in a "competitive" location!

[megan]

As Hon Jim alludes to, a gear collapse is most likely faulty maintenanceBeen trying, without luck, to find the report om QF 16 747-300 23 April 2000 that had the right wing gear collapse while making a U turn for departure at Rome. Memory is the strut came up through the upper wing skin and an engine damaged when it hit the runway.

[DaveReidUK]

I don't think it exists. In all likelihood, the comment on the ATSB site is still valid:

"The investigation by the Italian authorities is continuing. The ATSB has completed its contribution to the Italian investigation and plans to publish a copy of the final report on the ATSB website Australian Transport Safety Bureau (ATSB) (http://www.atsb.gov.au) when it is received from the Italian authorities."

It's by no means the only accident from many years ago that is still technically "under investigation" by the ANSV.

[zlin77]

Was an order for Continental Airlines but never delivered, taken up by Ansett Australia until their collapse, had a very spacious 2-2-1 Business Class, 25 seats and I think 185 Economy for a capacity of 210...

[Capt Quentin McHale]

Looking at the 1st photo in the 1st post. It looks as though the oleo has snapped clean in half, suggesting a possible flaw in the manufacture of the oleo and has taken this long to rear its ugly head. Nothing to do with an aircraft fault I believe. Open to correction though.

[megan]

I don't think it existsI saw that Dave, I do recall reading an extensive write up on the incident with photos, maybe a local aviation publication or local regulators safety mag.

[pattern_is_full]

It looks as though the oleo has snapped clean in half, suggesting a possible flaw in the manufacture of the oleo and has taken this long to rear its ugly head. Nothing to do with an aircraft fault I believe. Open to correction though.

It appears there is a (welded?) seam in the main shock strut just at that point, a few cms below the attachment flange for the jury strut/lock link - and a very clean break, as you say.

But whether that suggests a poor weld, or simply fatigue at a vulnerable spot, or both, or whatever, I leave to engineers with more knowledge, or the investigators.

[Krystal n chips]

As always with incidents, there's a multitude of potential causal factors which only the subsequent investigation will be able to determine resulted in the gear collapse.

That said, leaving aside, for now, possible maintenance / manufacturing error it would come as no surprise if more than one form of corrosion was discovered as has been the case many times in the past with similar u/c failures. This might help offer an insight therefore .....

https://www.aircraftsystemstech.com/2019/04/forms-of-corrosion-aircraft-corrosion.html

[Mr @ Spotty M]

The most likely cause is not from a manufacturing defect but from a previous restoration/overhaul of the gear.
Part of the blame must rest with the FAA & EASA authorities and others because originally there was no set procedure for a restoration (MRBR/MPD) requirement of the landing gear.
Each landing gear overhaul agency would perform there own procedure as there was never a set procedure to follow.
It was only around 5 or so years ago that authorities brought in set CMM or SB procedures which would be required to be meet, this to allow a FAA 8130 or EASA Form 1 to be issued for a restoration of the LDG to meet the MRB requirements.
This was not just for the Boeing 767 but other Boeing, Airbus and other manufactures aircraft.

[dixi188]

If the manufacturer of the landing gear didn't issue a CMM then how could anyone certify an overhaul/repair/restoration of the leg?
You need a statement along the lines of "I/we hereby certify that the Overhaul/Repair has been carried out in accordance with CMM 32-xx-xx rev xx" to issue an FAA 8130 or EASA form1.

[Mr @ Spotty M]

dixi188
Yes you are correct, but my understanding is that the CMM has all the various procedures just like an aircraft AMM has, but the issue was what of the hundreds of items within it that you need to perform to meet the requirement of a restoration.
The other issue is that the restoration as per the MRBR/MPD is for both LDG and components.
So what components have to be included within the requirement, it was a mess and the other issue was what parts would be scrapped as part of the restoration.
Anyone who has knowledge of how the MRBR is developed knows that airlines continuously supply details of findings from inspections, this enables increase in inspection intervals and the odd time a reduction is needed.
Corrosion findings will some times stop a structural inspection interval being increased, but this is where LDG becomes an issue.
Most airlines tend to swap out LDGs when they go for overhaul, they can't wait for the months it takes to send away for restoration and be returned.
So they fit a replacement from another source.
The issue is that very few airlines bother to get a full shop visit report, this from the LDG that they have swapped out for a serviceable one.
This LDG may have had a number of sections/parts that would have had corrosion and at what level.
This would be removed and repaired, or it could just be replaced, this is because it would be cheaper to replace and not repair.
This means the likes of Boeing and Airbus don't get the information that they need.
As you can see LDGs have always been a problem and that is why in my opinion you are going to continue to see this type of accident on aircraft in the future.

[Webby737]

It could well have been a manufacturing defect that was not found during overhaul.
Even the CMM procedures do not cover all the inspections that would need to be carried out. For example the CMM might state 'carry out Magnetic Particle Inspection of shock strut IAW ASTM 1441", it would then be up to the MRO or overhaul shop to write their own in house inspection procedure based on the guidelines of the ASTM.

[Wunwing]

megan

From memory the cause was an oleo failure of a swapped strut from a B747 100 series ,so a lot of time. When the unit was overhauled by the supplier, the inspection of the bore failed to identify that there was a minute spur of ferrous metal penetration into the chrome bore which set up a fatigue point.