Seems the big turd is showing its real colors. Long live the majestic B747-800

The "Majestic" 747-8 my A$$

Can't even get it properly certified. Boeing's had a base model since 1970...

Boeing holds firm orders for 36 747-8 aircraft

One of the biggest success of the history of aviation.

Any news from the EK order ?

And I thought that the Airbus v Boeing slanging matches were the reserve of Airliners.net :E

Serious question though...is this the second set of cracks to appear in the A380 wing? First the ribs(s) themselves, and now the rib feet? How big a job will this be to inspect / repair? I see one day mentioned for inspection...is that optimistic? And if a repair is required, I'm guessing each aircraft could be out for a number of weeks?

PS. If it ain't Boeing, I ain't going...unless the fare is cheaper, in which case, I might do a quick risk assessment, and decide to take the chance :}

Been said before, ALL jets get cracks, I reckon there might be something in the harder landings of the 380, have paxed on it more than a dozen times now, every arrival has been a teeth rattler, it must be such a delight to land on 23R at MAN:E

All airplanes crack, after 3 years in service it's a bit strange though, especially longitudinal cracks along machined pieces..

Sad that the stab tanks (3300 gallons each) cannot be used FAA directive due to flutter issues that will not be resolved by Boeing until 2013. Does EK need a short range / limited payload a/c somehow I doubt it.

Yahh I'd be disappointed if I bought an expensive car just to be told "don't use the rear seat, or the boot" it creates rear wheel hop, but hey, we'll have it sorted on the newer models...:}:}

Which A/C are you talking about here?

B747-8i & f

747-LOL I would call it.

How many design faults hasn't it had that have only been discovered after the a/c, crew and/or pax vanished. Fuel tanks, cargo door, aft pressure lock etc. Just wait for the carbon kite to show its true color.

Can't seem to find a single bus except perhaps the famous 320 outside paris, and still disputed if it was pilot error.

All cracked up
 

For all the best pilots in the world out there, who want some information from a 'simple' engineer, here's something that would hopefully clear up all the misinformation (or disinformation) out there.

No ribs on the A380 ever cracked. Its the RIB FEET (or attachment brackets) that fix the ribs to the wing lower skin that are cracking.

As of now, the four metallic ribs that Airbus claims to be primary structure in the wing don't have any cracks on their feet.

The rest (26, I think) of the CFRP ribs have feet that are cracked. Airbus claims (tongue-in-cheek) that these are secondary structure and give the wing its profile.

Now, to the cracks:

The original type 1 cracks, as they call them, originate from the fastner holes in the horizontal web of the rib feet. i.e. the rib feet are L-shaped in cross section, and the horizontal portion is bolted to the wing lower skin, while the vertical portion of the foot is bolted to the rib. The fastners that join the skin to the feet are an interference fit; so it seems that as the fastners are driven into the holes in the feet, the feet crack. The cracks radiate outwards from the holes. Some cracks have been severe enough to propagate to the edge of the material.

Interestingly, brand new wings (pre-assembly) received in Toulouse from the UK have been found to have multiple cracks. This is "GOOD" news, because it means the cracks are a production issue, and not fatigue related. One proposal from Airbus is to make these holes a clearance fit, as a quick fix. Material expansitivity, flex, etc. will all need to be re-assessed in the long run.

What is worrying are the type 2 cracks, which seem to be fatigue related, but are, thankfully, quite rare as of now. These originate from the edge of the feet, at the corner of the "L" and propogate inwards. Since a lot more research needs to be done to fix this, the quick fix is to replace the cracked feet with new (but still unmodified) ones. A mod program will be out as soon as Airbus figures out what is going on.

Down time for one airplane is around 3-5 days for inspection, and another 10-15 days for repairs (currently done by Airbus personnel).

Those are the facts, as I know them. No airline/manufacturer bashing. :)

From aviationweek
 

Airbus Adjusts A380 Assembly Process


Jan 26, 2012

By Robert Wall
http://www.aviationweek.com/media/im...a380AIRBUS.jpg Airbus has put in place changes to its A380 wing assembly process as part of its long-term fix to address cracking of wing components, but it also expects most of the A380s already built to require fixes as an interim measure.
Twenty of the more than 60 A380s in service worldwide are affected by a Jan. 20 European Aviation Safety Agency’s (EASA) airworthiness directive (AD) to inspect the aircraft for potential cracks of wing rib-feet. The findings by airline inspections that have unfolded in recent days are “in line with the expectations,” says Airbus Executive VP-Programs Tom Williams. The company expects to see cracks in most A380s already built.
Singapore Airlines, which has the most A380s affected, says four of its aircraft have undergone the process, and “there were findings during each inspection.” Of those, “one aircraft has already undergone repairs and is back in service. Repairs will be carried out before the remaining aircraft are returned to service,” says an airline representative.
The AD requires A380s with 1,800 flight cycles or more to undergo a detailed visual inspection within four days or 14 flight cycles, whichever occurs first. For aircraft with 1,300-1,800 flight cycles, the inspection has to take place within six weeks or 84 flight cycles, according to EASA. Some aircraft not yet affected by the directive because they have a lower number of flight cycles will undergo the process once they reach the EASA threshold or even before if they go into C Checks, Williams notes.
There are enough replacement wing rib-feet available to avoid a parts shortage that could affect the return of the aircraft to service.
At issue is an L-shaped bracket that attaches the wing skin to the ribs. Each wing has about 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. EASA says, “This condition, if not detected and corrected, could potentially affect structural integrity of the aeroplane.”
To avoid the problem on new-build aircraft, Airbus is already using shimming to reduce the strain applied when the wing skins are attacked to the ribs, thereby reducing the loads on the wing rib-feet. The gap between wing skin and rib, in the affected area, was about 1.5-2 mm, rather than 0.5 mm, causing unexpected strain on the rib-feet in the lower wing area near Rib 26 and Stringer 21.
Airbus also is changing the material of the part from an aluminum 7449 alloy to a stronger component. The overall effect will be to add 89 kg to the aircraft, Williams says.
Furthermore, Airbus is making changes to the interference fit fasteners because it judged the current arrangement contributory to the damage seen.
The inspection regime the airlines are undertaking involves draining the wing tanks and opening an access panel. Depending on local rules, the process takes a day or more. A repair action, if deemed necessary, can take several days.
Airbus stresses the issue is not a flight safety concern.
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 bear, leading to the cracks. But the aircraft maker determined that was not the case. EASA notes that this AD “is considered to be an interim action to immediately address this condition.” But, it adds, “Further mandatory actions might be considered” as a result of the ongoing investigation.
Wing changes being introduced on the A380 to boost the maximum takeoff weight to 574 from 569 metric tons should not create a new problem in this area, Airbus believes.

From hazy memory the loss of the horizontal stab by a 707 over Mt Fuji back in the 60's caused Boeing to check all the horizontal stabs on the 707 fleets at the time. 6 aircraft had undetected cracks that would have led to structural failure and since it's the horizontal stab parting company I'd assume the failure would always be catastrophic.

For all the rhetoric on this thread, both manufacturers, in spite of test and development programs, have learnt lessons the hard way.

But can we bash the Brits (who invented aviation as apparently KittyHawk was in Surrey) since they build the wings and deliver them new with cracks?

Yeap, Broughton factory, Hawarden Airport, Wales (UK) - that"s where the AB wings are made.
They are subsequently flown to Toulouse using Beluga aircraft (modified A300-600) for final assembly on Airbus airframes.

Avro used the place to build Lancaster and Wellington during the war, then Hawker-Siddely 125 after.
I landed there a couple of times.
No regular airline does fly to that piece of (nice) countryside.

And there was me thinking that KittyHawk was actually Bondi Beach and the first powered flight was by Bruce and Wayne Wright - the famous Sydney bicycle makers:D:D:D

B@gga off, Bruce and Wayne were in charge of the sheep dip.

the Don

good one WK :D

Not quite accurate, Bruce and Wayne was actually one person, he dressed up in shiney boots and fought and illegal war on behalf of a shady character called "Commissioner Gordon".
The Wrights on the other hand grew up in rural NSW, logged 47000000 hrs each on light twins before joining EK in the training dept, and inventing space travel :E

Falcon, I am surprised that you of all people would be belittling small aeroplane drivers. :E

The Don