Il n'y avait pas sujer dédié...
L'erreur est réparée...
Cet avion est en l'état incontournable (tout comme le CHinook !)
Il s'agit ici de la gestion de la flotte actuelle de C130
Et notamment la gestion du vieillissement du caisson central de voilure.
http://www.aviationweek.com/aw/generic/story.jsp?id=news/CENTER100709.xml&headline=Operators Eye C-130 Center Wing Box Options&channel=defense
Operators Eye C-130 Center Wing Box Options
Oct 7, 2009
Lee Ann Tegtmeier
Operators of mature C-130 Hercules have three good options for upgrading the aircraft's center wing box, the high-stress area where wings, empennage and landing gear meet. The first option is refurbishing the wing, the second option is installing a new standard wing and the third option is installing the enhanced service life wing, which flies on new C-130J models. Each choice extends the Hercules' service lives, at different costs.
About 1,500 C-130s operate in 72 countries, and of these, only 180 are J models, says Jim Grant, Lockheed Martin VP of air mobility. The bulk of them are B, E and H models with service life remaining. "We see customers operating them at least 30 years, across the customer base," with some more than 40 years, he says. That equates to about 25,000 hours equivalent service life, depending on how the aircraft fly.
With defense budgets getting smaller, many military operators want to lengthen the lives of their C-130s but face fatigue issues with the center wing box. Refurbishing or replacing the center wing box is a good way to do that. The lead time for new Lockheed Martin wings can be 28-30 months, so some operators want an option sooner, and for less cost.
TIMCO Aviation Services, MacAulay-Brown and Kellstrom developed a rehabilitation solution for C-130 center wing boxes (CWB) to restore them to "zero time," based on replacing more than 90% of parts with ones with the Lockheed Martin hologram. All of the CWB's critical structural components, including spars, wing planks and rainbow fittings, are new, says Ray Hauck, TIMCO SVP military business development. This solution is particularly designed for C-130B, E and H models and costs around $5 million to $6 million, with the functional check flight.
The zero-time CWB solution takes advantage of TIMCO's C-130 experience, which includes completing 123 CWB and programmed depot maintenance visits since the 1980s, when the MRO could concurrently refurbish the CWB and finish a PDM in 132 calendar days, from landing to takeoff. The U.S. Coast Guard is a current C-130 PDM customer and also is having TIMCO complete progressive structural inspection baseline work on some aircraft. TIMCO has completed heavy maintenance on C-130s from countries such as Bolivia and Ecuador, as well as for a few customers flying the C-130 commercial variant.
The TIMCO team's refurbished CWB package, including the new or refurbished wing, attaching hardware and new structural vertical beams, gives operators an airplane that can fly another five to 20 years, depending on what type of wing was installed.
TIMCO completes the project within 4/1000ths of an inch tolerance. "We've perfected this over the years" and have a very regimented work process flow detailing every task and tolerance, says Hauck. "That way you make schedule, you bring the quality to the table that needs to be there, and you keep your costs down."
The final steps TIMCO takes to insert new wings are similarly exacting, Hauck says: "You get the existing structure nailed in so nothing can move. You slide it in to make sure the alignment's perfect, then you change one beam at a time," precisely replacing the old with the new, "until your alignment is still dead on."
TIMCO has two "seed boxes" and wing panels ready to go for a customer interested in a refurbished CWB.
Grant says Lockheed looked at a refurbished option for customers with end-of-life CWBs but decided to stick to replacing them with new versions.
Lockheed Martin makes a new center wing box kit, which takes the OEM about five months to create, but the lead time for it is 28-30 months, according to Grant. Lockheed Martin has delivered 13 standard center wing box kits to the U.S. Air Force, its sole customer so far, and has 51 on order, he says. However, Lockheed Martin has discussed the CWB kit with L100 (the commercial, legacy version of the C-130) operators as well as a number of international customers, "but we haven't closed on those yet," says Grant.
The U.S. Air Force is installing standard center wing boxes, which have a service life of 38,000 equivalent base hours, on HC-130N, HC-130P, EC-130H and C-130H (FY74 and older), according to Jeff Huggett, C-130 modification chief and C-130 CWR program manager for 560 ACSS/GFLB at Robins AFB. Robins AFB receives a center wing box from Lockheed Martin every two to three weeks, and there have been no delivery delays, he says. It takes about five months to install the kit.
To maintain original manufacturing tolerances, Robins' 402nd Maintenance Wing uses traditional optics and modern laser trackers. Precision optical alignment occurs multiple times during the replacement process. Engineers use extensive shoring and fixtures to level and restrain aircraft for the center wing box modification; fixtures around the aircraft were recapitalized from a similar replacement program that took place during the 1990s, Huggett notes. The unit also developed tooling, shop aids, work stands and processes to ensure a repeatable process, he says.
The enhanced service life wing on the C-130Js have two to three times the life span of previous models because of better structural support, including more robust stringers, upper and lower rainbow fittings and engine mounts. Huggett says the enhanced service life wing box is designed to serve as a form, fit and function replacement, although its installation requires some plumbing and wire routing modifications. It also costs about $300,000 more than the standard center wing box.
The U.S. Air Force is installing the enhanced center wing box on special mission aircraft with more difficult mission flight profiles. These include MC-130H, AC-130U and C-130H (FY78 and newer). So far, Lockheed has delivered seven ESL kits but has 37 on order.
Lockheed Martin's Grant says the international community is looking at how to bundle CNS/ATM avionics upgrades with a CWB replacement, particularly for C-130H customers who want to fly their aircraft another 20 years. Operators considering this substantial avionics investment most likely would upgrade their center wing box simultaneously, believes Grant. "Because the center wing box lead time is in the 28-30 month range, the avionics could clearly be done in that time period, as well," he says.
Grant thinks the enhanced wing is a particularly good investment for H models, some of which have been flying at high operations tempo in Iraq or Afghanistan, "so they're flying ahead of where they thought they'd be."
Hercules operators may refurbish or replace this high-stress area of the aircraft.
Plus de 1500 Hercules sont en service dont finalement une faible proportion de modèles –J.
Certains atteignent déjà 25000 équivalent heures de vol.
Le caisson central de voilure concentre les contraintes en provenance des ailes, du train et de l’empennage.
Trois options s’offrent aux utilisateurs pour augmenter le potentiel de cette pièce
1) Réfection de l’aile (juste le caisson ?) :5 à 6 millions et extension de vie de 20 ans
2) Changement de l’aile par une identique (juste le caisson ?) : prix ? solution utilisée par l’USAF, 5 mois d’immobilisation, potentiel 38 000 équivalent heures
3) Changement pour l’aile du C130J (juste le caisson ?) : + 300 000 € par rapport à la solution précédente.
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