Aussie engineers say A380 fleet should be grounded

Cracks in wings of the A-380....already?
 
Aussies have been trying to ground the entire P&W PT6-A fleet for years. They tend to over-react a bit, IMO.
 
wabower said:
Aussies have been trying to ground the entire P&W PT6-A fleet for years. They tend to over-react a bit, IMO.
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While both of these statements are true, the second more so than you may realize lol, but when structural bonds and elements inside the wing are breaking, I gotta agree with them. The state of real knowledge and engineering of Carbon Fiber structures is no where as solid and advanced as most people seem too think. Personally I don't trust CF enough to do a sole material structural lay up with it on anything that has to serve a critical function for more than 6 years. CF engineered structures are breaking right and left in the marine industry. Back in the day we could race a CF chassis 5 years; somewhere in the middle of season six the whole structure would disintegrate.
 
sailplanes started using carbon fibers for spars at least back in the early 80's...
 
tonycondon said:
sailplanes started using carbon fibers for spars at least back in the early 80's...
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Yep, but they don't see near the cycles in its lifetime that an airliner sees in a day and the load factors imposed on gliders are orders of magnitude below that of a commercial powered aircraft. Add to that the vibrations set up by the mechanical systems in a powered aircraft, and you are beyond apples and oranges, you're comparing apples to horses.
 
Here's a question - what do the test airframes show? If they show a similar pattern (particularly the fatigue test one), then there may not be any concern.

On the other hand if they don't, then either the production units are different or the testing didn't simulate reality very well.

I remember Boeing had a problem with an alloy used on 777 interiors - it developed cracks that were all on the surface, and they decided to use something different because even though the material was structurally sound it just looked... bad.
 
I flew across the Atlantic recently and I was very glad to be in a 767, a tried and true design.
 
tonycondon said:
sailplanes started using carbon fibers for spars at least back in the early 80's...
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Many of the high g rated acro planes also used carbon fiber in the 90's such as the Extra seriesand some of the Sukhoi series, etc. In current time, the list now includes the MX series, the Edge series, etc.
 
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The A380 is conventional construction, not composite.
 
Henning said:
Then I don't understand, are the ribs glued in?
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This from Aviation Week:

Airbus says it has already developed a fix to wing cracking found on some Airbus A380s.

The cracks, first reported by the Sydney Morning Herald, have been seen by at least Qantas and Singapore Airlines. The cracks were first found on the Qantas A380 that suffered an uncontained engine failure with one of its four Trent 900 engines two years ago.

Airbus confirms the cracking on “some non-critical wing rib-skin attachments on a limited number of A380 aircraft.” The aircraft maker adds that safe operations of the fleet are not affected and no flight limitations are being put on the A380.

Airbus says a inspection and repair process has been identified, although it would not detail how the fix is made. The repair is being done as part of four-year maintenance checks, it adds.

The approach has been validated by the European Aviation Safety Agency, Airbus says.
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Henning said:
Then I don't understand, are the ribs glued in?
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IIRC, I saw a video showing spin welding, but that may only have been the skin/skin edge bonding. They showed a machine that looked something like a router bit to my admittedly uneducated eyes.
 
Cap'n Jack said:
IIRC, I saw a video showing spin welding, but that may only have been the skin/skin edge bonding. They showed a machine that looked something like a router bit to my admittedly uneducated eyes.
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That was friction stir welding on the aluminum spars, IIRC. I seem to remember that either no one could make spars big enough in one piece, or they couldn't be transported, or something.
So the friction stir welding essentially made them one piece of aluminum.
 
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