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.

Option One

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.