Recent Topics
Spiral dynamics of the solar system
by jrustles
09/02/14 01:36 PM
Imminent Terrorist Attack Warning
by friendly_jacek
09/02/14 01:36 PM
Fast food workers plan Thursday strike f
by LT4 Vette
09/02/14 01:15 PM
GM To Install Eye/Head Tracking Systems in Autos.
by sleddriver
09/02/14 12:42 PM
STP Global Extended Life coolant?
by bullwinkle
09/02/14 12:25 PM
coolant mix
by BigD7
09/02/14 11:59 AM
First time post, looking for thoughts on UOA
by Streetside
09/02/14 11:51 AM
Polaris ranger 570 efi?
by tinman11
09/02/14 11:48 AM
5k OCI on Hyundai Sonata 2.0 Turbo
by syn_all_the_way
09/02/14 11:36 AM
Replaced cracked flexplate 95 Toyota T100
by chestand
09/02/14 11:19 AM
Snow tire/made in USA rant
by faramir9
09/02/14 11:13 AM
2011 Ram 1500 Differential and Transfer Case
by JasonK94Z
09/02/14 10:17 AM
Newest Members
SparkSVT, grumpyoldman, jbl_91762, PapasGuy, fanie
51170 Registered Users
Who's Online
100 registered (901Memphis, 3800Series, AandPDan, 123Saab, abycat, 9 invisible), 1966 Guests and 219 Spiders online.
Key: Admin, Global Mod, Mod
Forum Stats
51170 Members
64 Forums
218681 Topics
3448299 Posts

Max Online: 2862 @ 07/07/14 03:10 PM
Donate to BITOG

Topic Options
#2651417 - 06/11/12 06:14 PM New Info on A380 Wing
MolaKule Offline


Registered: 06/05/02
Posts: 14402
Loc: Midwest
A380 Wing Repairs To Take 60 Days
AWIN First Jun10, 2012
Jens Flottau jens_flottau@aviationweek.com
Beijing


Airlines may have to ground their Airbus A380s for 60 days to repair the aircraft’s wings, two A380 operators told Aviation Week on the sidelines of the International Air Transport Association ’s annual general meeting in Beijing.

Tim Clark, president of Emirates Airline, says around 30,000 maintenance man-hours are required to make the fix developed by Airbus . Airbus is performing the work because Emirates does not have the manpower to handle the task, Clark says.
Airbus says it is also developing a repair schedule that would allow the airlines to perform the work during regular C checks. But that would mean the repairs would be spread out over several years and would make the aircraft subject to a more rigorous check regime.

Lufthansa’s executive board member Carsten Spohr says that with its current fleet of six aircraft, the airline will technically have one of its A380s grounded for one year until all of them are repaired.

Type 2 cracks have been discovered in wing rib feet, the connecting parts between the rib and the wing skin, in most in-service aircraft. Because a permanent fix will not be available until next year, a total of 120 aircraft will have to be repaired. Airbus says about one-third of the 76 in service-aircraft already have incorporated the repairs.

The retrofit entails replacing all of the 23 hybrid ribs (made of a mix of 7449 aluminum and composite) with all-metallic ribs made of 7010 alloy. The rib feet also will be redesigned to strengthen them, and an inspection manhole in the area where the cracking occurs will be strengthened.

There are several causes for the wing-component cracking problem. One is the use of a specific aluminum alloy (7449) and its heat treatment. The alloy saves weight, but it rendered the component more brittle, which caused cracking. Another is in attaching the wing skin to the ribs, where excessive loads were placed on components during assembly. The situation was compounded by a failure to properly account for the temperature-induced material expansion and contraction during operations.

EASA still has to sign off on the fix . That will require validating the proposed repair during flight trials using an instrumented Airbus A380 test aircraft.

To avoid future problems, Airbus will make changes beyond those immediately needed. For instance, ribs 48 and 49, at the outer end of the wing , will be replaced even though no cracks have been found in them because they are made with 7449 aluminum alloy. The ribs will be replaced with ones made with a more traditional alloy (7010).


Edited by MolaKule (06/11/12 06:16 PM)
_________________________
"IDIOTITiS: Causes the brain to shut down and the mouth to keep talking. Thousands affected. Best defense, slap and run." Donald Duck smile

Top
#2651443 - 06/11/12 06:34 PM Re: New Info on A380 Wing [Re: MolaKule]
azsynthetic Offline


Registered: 06/01/07
Posts: 1221
Loc: Phoenix AZ
Yup, Airbus told us to delay delivering A380 shipset last month due to lack of money and aircraft to put them in. I will be totally surprised if Airbus can sell 300 birds by 2015. EU carbon tax is not helping either.

Top
#2651525 - 06/11/12 07:34 PM Re: New Info on A380 Wing [Re: MolaKule]
dkryan Offline


Registered: 04/11/03
Posts: 1707
Loc: Cincinnati
Thanks, Molakule.

According to AW&ST's latest edition, Airbus is using the 7010 alloy in the A350 series to avoid the A380 nightmare.
_________________________
2014 Nissan Altima SL
Pennzoil Ultra/Purolator Syn Filter

2005 Highlander V6 -
Green Earth Technologies 5w-30/M-1 filter/Amsoil ATF & gear lube

Top
#2651553 - 06/11/12 08:02 PM Re: New Info on A380 Wing [Re: MolaKule]
bepperb Offline


Registered: 01/10/08
Posts: 4657
Loc: Milwaukee, WI
30,000 man hours costs a bit over a million dollars for skilled labor in the US. Let's say each plane costs 2 million to fix all said and done. That's not peanuts but the plane costs 400 million so in relative terms I doubt this is that big of a deal. They'll lose way more on lost orders and delayed delivery than it costs to fix the planes they have.

But my first reaction was certainly... 30,000 hours... how many hours does it take to just make a whole new wing (but the more I thought about it, maybe 10 times that).
_________________________
2004 Highlander 2.4
2011 Toyota Sienna 3.5
Recently Gone:
2006 Accord 2.4l K24A8
1993 Kawi EX 500

Top
#2651675 - 06/11/12 09:58 PM Re: New Info on A380 Wing [Re: MolaKule]
azsynthetic Offline


Registered: 06/01/07
Posts: 1221
Loc: Phoenix AZ
Where do you think Airbus going to find the manpower to do all the fix at different locations? 30,000 hours is an estimate for just the fix. It does not include redesign, EASA and FAA approval, retooling, production line modification, subcontractors lead time for parts, etc. 30,000 hours in the aircraft industries is closer to $3 million. At one time Boeing was lending us their engineers because we could not find people to do the job. I highly doubt Airbus has the spare manpower to do the fix nor the airlines willing to ground the fleet. Eventually I think it will be done at C checks.

Top
#2651968 - 06/12/12 10:10 AM Re: New Info on A380 Wing [Re: MolaKule]
MNgopher Offline


Registered: 09/17/02
Posts: 2942
Loc: Lakeville, MN
Saw some basic math on another forum I visit. Airbus has set aside approximately $250 million to cover the cost of wing repairs, with 71 frames needing the repairs. Breaks down to about $3.5 million per airframe. The full cost of labor (benis, etc... included) is closer to $90 an hour, so if we assume the cost is only labor, you get 38,000 hours per airframe. So figure about $700,000 in parts and $2.7 million per airframe in labor. Airbus has indicated the work can be accomplished in about 60 days per airframe.

I agree this will end up being a C-check item. Can't see it going any other way. Only problem is that more detailed monitoring inspections will need to be continued until the fix is done.

Not good for a program that has always had dubious prospects for being a profitable airframe for the manufacturer.

Top
#2651990 - 06/12/12 10:53 AM Re: New Info on A380 Wing [Re: bepperb]
757guy Offline


Registered: 12/30/09
Posts: 199
Loc: MN
Originally Posted By: bepperb
30,000 man hours costs a bit over a million dollars for skilled labor in the US. Let's say each plane costs 2 million to fix all said and done. That's not peanuts but the plane costs 400 million so in relative terms I doubt this is that big of a deal. They'll lose way more on lost orders and delayed delivery than it costs to fix the planes they have.

But my first reaction was certainly... 30,000 hours... how many hours does it take to just make a whole new wing (but the more I thought about it, maybe 10 times that).


A $2M repair that takes an aircraft out of service for three months is very, very expensive. Assuming an average daily aircraft utilization of 13 hours a day X 90 = 1170 revenue hours lost. If that aircraft generates $20,000 per revenue hour (only a guess), that's a loss of over $23,400,000 of revenue per aircraft over the 90 day time period.

Now that's expensive!

757 Guy


Edited by 757guy (06/12/12 10:59 AM)

Top
#2652712 - 06/13/12 12:02 AM Re: New Info on A380 Wing [Re: MolaKule]
azsynthetic Offline


Registered: 06/01/07
Posts: 1221
Loc: Phoenix AZ
The B777 is already over $20,000 per revenue hour and the A380 supposes to best that by 20%.

Top
#2653921 - 06/14/12 08:21 AM Re: New Info on A380 Wing [Re: MolaKule]
azsynthetic Offline


Registered: 06/01/07
Posts: 1221
Loc: Phoenix AZ
Here is Emirates estimates of actual aircraft revenue loss for this year from A380 repairs.

http://www.arabianbusiness.com/a380-grounding-cost-us-30m-month-emirates-exec-461954.html

Top
#2663862 - 06/24/12 07:20 PM Re: New Info on A380 Wing [Re: MolaKule]
Kestas Offline



Registered: 06/04/02
Posts: 10791
Loc: The Motor City
Originally Posted By: MolaKule
There are several causes for the wing-component cracking problem. One is the use of a specific aluminum alloy (7449) and its heat treatment. The alloy saves weight, but it rendered the component more brittle, which caused cracking.

To avoid future problems, Airbus will make changes beyond those immediately needed. For instance, ribs 48 and 49, at the outer end of the wing , will be replaced even though no cracks have been found in them because they are made with 7449 aluminum alloy. The ribs will be replaced with ones made with a more traditional alloy (7010).

This reflects a troubling trend I've seen over the three decades in my business. Design engineers seek higher strength materials in an effort to reduce weight. They look at the material property data and seek out the material and heat treatment that gives them the best strength. This looks good for their computer generated stress calculations on 3-D parts. But then they're surprized with the finished part when they run into problems and their material lacks robustness and exhibits brittle character.

Top
#2663939 - 06/24/12 08:47 PM Re: New Info on A380 Wing [Re: MolaKule]
MolaKule Offline


Registered: 06/05/02
Posts: 14402
Loc: Midwest
Fatigue analysis should have caught this unless the materials properties were incorrect.

Lab fatigue testing should have shown problems as well.

Another possibility is they later found the local wing loads turned out to be greater than orginally calculated.
_________________________
"IDIOTITiS: Causes the brain to shut down and the mouth to keep talking. Thousands affected. Best defense, slap and run." Donald Duck smile

Top
#2664288 - 06/25/12 08:09 AM Re: New Info on A380 Wing [Re: MolaKule]
azsynthetic Offline


Registered: 06/01/07
Posts: 1221
Loc: Phoenix AZ
Finite element analysis on maximum wing stress loading is done on a one pass basis compares to actual aircraft loading over time. The Airbus analysis is correct for a one pass but in reality it degraded over time. This is why the cracks are not consistent between all aircrafts. The major issue here is that there is a flaw in the manufacturing process that introduces addition stresses to the wing that are not accounted for in the finite element analysis. In theory, the manufacturing process can be revised to eliminate the addittional wing stress, but since Airbus does not want to take a chance they have decided to go back to the traditional aluminum materials.

Top
#2664699 - 06/25/12 04:49 PM Re: New Info on A380 Wing [Re: MolaKule]
Shannow Offline


Registered: 12/12/02
Posts: 26344
Loc: a prison island
It's pretty common in any F.E. model to have to "tune" it to actual operational failures.

We had a particular blade failure in a 410 blade that failed at 30 years and 190,000 hours...the blade had been modelled to death in the 70s and 80s. But the failure location eventually fingered a 20 node "wavy washer" vibration in the bladed disk that gave an infinite fatigue life in theory, but lead to 13 month failure after the introduction of a chloride pit at that exact point of crack inititation.

Bench testing of small samples, accelerated fatigue, strain ageing (and in my industry thermal fatigue) are great to get a design off the table, but in macro world, field engineers will always be finding "stuff that shouldn't have broken", then learn why.

Biggie in my industry is macro properties of "new" steels like P91, and the vagaries of heat treatment on large fabrications.

This IS pretty early 'though.

Top
#2669149 - 06/29/12 06:50 PM Re: New Info on A380 Wing [Re: MolaKule]
MolaKule Offline


Registered: 06/05/02
Posts: 14402
Loc: Midwest
Quote:
EASA Expands A380 Wing Inspection Guidance
AWIN First Jun28, 2012
Robert Wall wall@aviationweek.com
LONDON


The European Aviation Safety Agency has set the expanded inspection intervals for A380 wing component cracks as the regulator continues to work with Airbus to approve a final fix for the problem.

The airworthiness directive is aimed at operators that have had their A380s undergo a first round of interim repairs to address cracks in some wing rib-feet on the aircraft. The updated guidance sets two different inspection requirements. A first wave of aircraft to receive an interim fix now need to undergo inspection after another 560 flight cycles, which is the equivalent of around one year of service.

Airbus later modified the interim fix process to provide a more robust solution where all lower panel rib booms sections have been replaced. Aircraft that underwent the latter process can fly up to 1,200 flight cycles , or around two years, before being required to undergo a another inspection.

Most of the aircraft will be governed by the 560 flight cycle regime; Airbus expects to have a final fix approved and ready for installation by the time airlines hit those inspection point.

The final fix is to restore the A380 wing’s full life cycle of 19,000 lift cycles.

Up to now, airlines were operating under a directive that required inspection by the time A380s reach 1,300 flight cycles .

Airbus expects 120 or so A380s need to be retrofitted before aircraft will be delivered with the final fix installed on the product line.

Airbus is absorbing much of the costs associated with the wing cracks , although some airlines are looking for greater compensation to offset operational losses incurred when the A380 is out of service for the repair. Retrofitting the final fix could take 60 days, says Emirates Airlines chief executive Tim Clark.
_________________________
"IDIOTITiS: Causes the brain to shut down and the mouth to keep talking. Thousands affected. Best defense, slap and run." Donald Duck smile

Top