More cracks in scarebus wings

[PR3D4TOR]

Use your imagination willis. 

"Following an unscheduled internal inspection of an A380 wing, some rib feet have been found with cracks originating from the rib to skin panel attachment holes (Type 1 cracks according to Airbus All Operator Telex (AOT) terminology).

Further to this finding, inspections were carried out on a number of other aeroplanes where further cracks have been found. During one of those inspections, a new form of rib foot cracking originating from the forward and aft edges of the vertical web of the rib feet has been identified (Type 2 cracks according to Airbus AOT terminology). The new form of cracking is more significant than the original rib foot hole cracking. It has been determined that the Type 2 cracks may develop on other aeroplanes after a period of time in service.

This condition, if not detected and corrected, could potentially affect the structural integrity of the aeroplane."

It's the rib feet brackets that have been discussed at length earlier in this thread.

“Critical” has a different meaning in engineering terms. Engineers design redundancies in structures for this exact reason. There’s a whole list of parts on an airplane that the FAA will let you take off without, or at least without them being functional. Airliners are massively over-engineered. Twin jets have to be able to take off, land, and if they’re ETOPS fly for a hell of a long time on one engine. So arguably the second engine isn't even “critical”… although I’m not seriously suggesting that.
 
The Aviation Week article says: “Each wing has around 2,000 L-shaped brackets (30-40 per rib, with 60 ribs per wing), so the failure of one bracket is not seen as a safety issue.” These are the parts that distribute the aerodynamic loads from the wing skin to the rib/spar assembly. Essentially they’re secondary load bearing structure. If you have enough of them fail, you could potentially lose a wing skin section but the probability of that is exceedingly low owing to the shear number of brackets. I wouldn't start worrying till you hear stories of cracked wing spars or other primary structure.

[PR3D4TOR]

From the Aviation Week article:

"The inspection is relatively simple, the wing expert says, requiring drainage of the relevant tanks for a visual inspection. However, the time to drain the tanks likely means an aircraft is out of service at least 24 hours, depending on local safety rules. If a bracket is found to have cracked, it needs immediate replacement, which could take a few days.

As part of the root cause analysis, Airbus instrumented one of its own aircraft to assess whether it had erroneously estimated the loads the wing would see, leading to the cracks. But the aircraft maker determined that was not the case. Instead, it found that the likely culprit is the assembly process, which imparts too much stress on the bracket when the wing skin is attached to the rib. The part itself is not being redesigned, but the assembly process is being changed for the long-term solution."

http://www.aviationweek.com/aw/generic/story_channel.jsp?channel=mro&id=news/awx/2012/01/19/awx_01_19_2012_p0-415962.xml&headline=EASA%20Demands%20A380%20Wing%20Crack%20Inspections

[colmbo]

Instead, it found that the likely culprit is the assembly process, which imparts too much stress on the bracket when the wing skin is attached to the rib. The part itself is not being redesigned, but the assembly process is being changed for the long-term solution."

Reminds me of the engine attach bolts on the DC-10.  Companies were stressing the assembly during engine changes -- engine feel off a DC-10 after takeoff leading to crash.

[Shuffler]

hmm so those accident reports include things like airstrikes of birds and such. Not just failures of some sort.


Maybe I missed it... was the french flight in there too? I believe that one was pilot error so if it is then they include that also.

Seems it would require more indepth analysis to dig out the actual failures of the aircraft involved.

[PR3D4TOR]

Almost all, if not all, accidents with modern airliners are human error, either in the cockpit or in the workshop. The very few that isn't is probably weather related. There is little to chose between Boeing and Airbus in terms of safety, procurement cost or direct operating cost these days... Which is why this whole thread is silly.

[VonMessa]

Almost all, if not all, accidents with modern airliners are human error, either in the cockpit or in the workshop. The very few that isn't is probably weather related. There is little to chose between Boeing and Airbus in terms of safety, procurement cost or direct operating cost these days... Which is why this whole thread is silly.

Airbus employee?  

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

[icepac]

Go here and get the opinions of the guys who have thousands of hours in each.

http://www.pprune.org/

[PR3D4TOR]

Clerks! Love that movie!  

If this thread had been titled "More cracks in [insert derogatory nickname for Boeing] wings" I would be here slugging for Boeing. I guess I'm just adverse to blind fanboiism and scare tactics. I don't know why Airbus doesn't have its own fanboi club. Maybe it's because Airbus is more of an international company and the euros don't identify with it as much as Americans do with Boeing.

[VonMessa]

Clerks! Love that movie!  

If this thread had been titled "More cracks in [insert derogatory nickname for Boeing] wings" I would be here slugging for Boeing. I guess I'm just adverse to blind fanboiism and scare tactics. I don't know why Airbus doesn't have its own fanboi club. Maybe it's because Airbus is more of an international company and the euros don't identify with it as much as Americans do with Boeing.

They ALL scare me when I'm not the one doing the inspection...

Hence the reason for building my own

[PR3D4TOR]

What are you building? A kit job or home brew?

[VonMessa]

What are you building? A kit job or home brew?

http://en.wikipedia.org/wiki/Barrows_Bearhawk

Scratch build, nowhere near completed.  May buy individual kit parts (spars, etc) unless I stumble across an 8' break.

[PR3D4TOR]

Always wanted to build my own plane ever since I saw that english dude build a Europa on Discovery. Need to find the time, money and space.

[VonMessa]

Always wanted to build my own plane ever since I saw that english dude build a Europa on Discovery. Need to find the time, money and space.

Honestly, it takes more time than anything...

I visited the designer of this plane back in May of 2011.

He has a modest farm (runway in valley between mountains), and a shop that is just as modest (perhaps 30' x 30')

No fancy tools, machines, etc.  Just the basic hammers, form blocks, gas welder, 8' brake and fabric covering tools.  Spartan to say the least.

Not even a fully enclosed hanger

[VonMessa]

Not even a fancy crapper (except for the obligatory moon, of course)

[PR3D4TOR]

Lol! That looks wonderful. The perfect place to build a plane and fly it!


Here's that show I mentioned. Love all those exotic experimentals...

http://www.youtube.com/watch?v=pUN9z7w8gwg