Depot Nightmares

Jan. 1, 2010

Take a look inside Building 48 at Robins AFB, Ga., and you will see the Air Force’s venerable F-15 fighter force getting the equivalent of a massive booster shot—courtesy of mechanics and other technicians who work in the fighter’s programmed depot maintenance shop. It certainly needs a boost.

All of the Air Force’s F-15 models come through this shop for the programmed depot maintenance (PDM) cycle. That is where F-15 major modifications take place. Around the building, wings are being disassembled, while stabilizers and tail assemblies are being inspected by technicians looking for signs of trouble.

“This is a moving line, much like a factory,” said Keith Gilstrap, production chief of the 561st Aircraft Maintenance Squadron A Flight.

A mechanic inspects the upper fuselage of a C-5 at Warner Robins Air Logistics Center, Ga. (USAF photo)

Indeed it is. Warner Robins Air Logistics Center, the principal enterprise at Robins Air Force Base, is also the front line of an unnoticed war—the fight to keep old, battle-worn aircraft in fighting trim.

From re-engineering obsolete parts to retooling avionics, technicians across the 2,200-acre complex are tackling problems rarely, if ever, faced before.

Gilstrap, a former F-15 crew chief, said the fighter fleet looks older and older every time a new airframe arrives and gets cracked open.

“The thing is, the airframe is fundamentally sound,” he explained, next to the midsection of an F-15E. “You just have to remember, you have to keep a close track of where stress and deterioration is happening.”

No fighter category better embodies the maintenance challenge than the F-15 fleet—whose average age is pushing north of 26 years. Depot workers routinely find problems in the rudder controls during operations checks, increased wear and tear on the vertical stabilizers, and significant deterioration in the electrical wiring of the rear tail assembly.

“There’s just a lot of rubbing and fraying on those components now, just as a result from how those parts move when flying,” said Andree Zanders, a veteran aircraft electrician.

Overall, the situation often can be nightmarish.

One of many F-15 depot maintenance areas at the ALC. (USAF photo by Gary Cutrell)

Opening the Hiring Valve

It was to here, “Eagle Country,” that the Air Force sent every one of its F-15s during the fleetwide stand-down imposed in the wake of the November 2007 breakup of a Missouri Air Guard F-15. The fighter broke in half during a training exercise, an accident caused by a faulty longeron. The depot workers here put in long hours to comb over all the aircraft and were able to clear the entire fleet through the depot in about six months.

Now, USAF wants to pare down its legacy fleet—retire older models and modernize the newest airframes to get more life out of them.

For the workers at Robins, this process began ramping up in November when work on modernizing components began for 178 of the Air Force’s F-15Cs.

Gilstrap anticipated each effort—where workers will strip out all old wiring components from the aircraft and put in new wiring harnesses—to take about 195 days. While the largest feature of the upgrade is the installation of new active electronically scanned array (AESA) radar, a string of structural replacements will also go into each fighter eventually, including ribbing and parts of the flight-control system. New harnesses will help to get the aircraft back to their squadrons sooner.

“We’re basically rebuilding these aircraft when they come in,” said Robert Riggin, an F-15 A Flight chief. “We’re going to fill up a lot of boxes with old wiring harnesses, but the end result is going to be a far better aircraft.”

Warner Robins, much like its counterparts at Tinker AFB, Okla., and Hill AFB, Utah, is unusual as far as Air Force installations go. It is dominated by civil service employees rather than service members. Of the 402nd Maintenance Wing’s 8,000-plus personnel, only 150 or so are military, said Brig. Gen. Lee K. Levy, the wing’s commander.

Levy, a career maintenance and munitions officer, called the base’s civilians “artisans,” a term he admitted makes a few people’s eyebrows rise. “When you see what they do with these airplanes, … when you watch them take out a center wing box and put it back in for an aircraft that was built in 1964, … that’s an artisan,” Levy said.

A maintainer sprays paintdissolving solvent on a C-130 as part of the programmed depot maintenance work flow. (USAF photo)

Some of the Air Force’s most in-demand assets visit Robins for their PDM cycles, including all of Air Force Special Operations Command’s C-130 variants, F-15s, C-17s (though the airlifter is maintained through a partnership with Boeing, different from a traditional PDM cycle), C-5s, and others.

Several factors have combined to increase the ALC’s workload in the last few years: a raft of modernization initiatives, increasing labor costs as a result of more wear and tear on the systems, and the expansion of fields such as software engineering for newer systems such as the Global Hawk unmanned aerial vehicle program and the F-22 Raptor.

“We’ve seen a fairly significant increase in the workload requirements and we’ve been opening the hiring valve pretty wide,” Levy said, adding that Fiscal 2010 will see an increase in work on all aspects of maintenance and sustainment.

Expansions in the C-17 program are under way, to keep pace with upgrades (such as the large aircraft infrared countermeasures, combat lighting modifications, and Ethernet upgrades for older blocks), the C-130 wing box replacement program, and the F-15 modernization effort.

Highlighting the C-5, Levy noted PDM hours have “expanded considerably” to get the aircraft up to spec—not a unique case among the assets his wing is responsible for.

“If an aircraft takes me 20,000 hours for a PDM, that equates to a certain number of people,” he said. “But if the aircraft is now taking 25,000 hours, we have to buy the extra labor to do that work.” The assessment is borne out in the Air Force’s own readiness statistics, which show dollars marked for depot maintenance have steadily risen in the last few years, going from $33 billion in Fiscal 2007 to $43 billion in Fiscal 2009.

Down on the floor of one of the C-5 hangars at Robins, the mechanics and technicians relay the story behind the numbers. “We’ve definitely been spending more time on the aircraft when they come in,” said Lamar Wallace, a 12-year veteran C-5 sheet metal mechanic. “More [work] on areas like the aft ramps, … gears, and other places.”

James Skipper works on the No. 4 engine of a C-130 undergoing High Velocity Maintenance in depot. (USAF photo by Sue Sapp)

Daunting Workload

Oftentimes, “flow days”—the amount of time an aircraft spends in depot—are added on, so engineers can come down, consult with the sheet metal mechanics, and go back to remanufacture a part not readily available anymore, said Clay Scarborough, another sheet metal technician.

“You’re starting to see parts fail that I’ve never seen fail,” said Danny Hatcher, a C-5 flight-control technician. As a rule of thumb, once line inspectors went over the aircraft, Hatcher’s section would routinely switch out about 25 parts or so flagged for replacement. “Now, it’s routinely 50 or more.” Spare parts are often a challenge when trying to cut down on flow days, Wallace noted, with a combination of availability and obsolescence often at fault. It is not unheard of for mechanics to install parts on the aircraft as it is about to taxi out to the runway for flight-test certification, he added.

At the far end of Robins’ runway, a quartet of hangars houses the C-130 PDM shop, where the Air Force’s in-demand tactical airlifters, as well as AFSOC’s special mission variants and gunships, are stripped down.

George Hoffman, supervisor with the 560th Aircraft Maintenance Squadron C-130 shop, said that due to their high operations tempo and limited numbers, AC-130 Gunships and MC-130 Combat Talons are often pushed hard through depot cycles, with mechanics holding down 12-hour shifts to get the aircraft back in service. The workload is daunting, as the aircraft are progressively seeing more corrosion in areas such as the landing gear components, the bow beams, and ramps. One Combat Talon in the shop, nearly finished with its depot cycle in mid-November, had at least 100 parts repaired or replaced for corrosion since its arrival in April, said Robert Hall, a sheet metal mechanic.

Ramp corrosion is particularly acute in the C-130s operating in the desert, Hall noted, pointing to visible deterioration on the rear ramp of a Hercules.

“We used to never change these,” Hall said, indicating one of the aircraft’s sloping longerons, a long beam on either side of the rear cargo door that essentially holds up the entire tail of the aircraft. “Now, we’re switching out about 10 a year.”

Painters from the 402nd Corrosion Control Flight prep the wing of a C-5 for thepainting process. (USAF photo by Sue Sapp)

Aside from the metal being replaced on the aircraft, the avionics and components are posing their own challenges, said Mike Poole, the Group Control Center flight chief for the 402nd Electronics Maintenance Group. Responsible for components in 328 different systems, from laser guided bomb kits to transponders to one of the few remaining printed wiring board shops in the United States for reverse engineering obsolete circuit boards, Poole manages a wide range of experts.

As with aircraft mechanics, limitations often revolve around parts, where the shop will do “cross canning” (cannibalizing) in some cases—swapping out a part on one component to put in another one with a higher priority. “They’re getting the job done,” Poole said of his technicians. “We might not be able to repair one, but we can pull another one in and work on it instead.”

For ALC leadership, the increasing time, cost, and manpower pressures on the depot workforce are receiving a great amount of attention—and they are being addressed with a range of new initiatives and experiments.

The Air Force is studying how it manages its funding strategies for weapons systems, said Maj. Gen. Polly A. Peyer, the Warner Robins ALC commander. “In the old days, we just looked at percent funded and we made a value judgment as to whether we were challenged or not,” she said. “Now, we do it by portfolio—global reach, vigilance, and power.”

Peyer’s team at the ALC has devised a strategic plan to improve performance by better integrating the personnel, mission, and culture of the installation. Called P Cubed I—for people, process, performance, and infrastructure—it aims to integrate labor and management relations with process improvement efforts and innovations, develop leadership and training initiatives, better conserve resources, and improve customer support. “If you marry those together, that’s where your performance comes from,” said Peyer.

Becoming Proactive

Peyer also has high hopes for High Velocity Maintenance, an initiative where the inspection regime is spread out and advance teams more thoroughly diagnose an aircraft for PDM. Rather than a C-130 arriving in depot every five to six years, it will arrive every 18 months but stay only 45 days or so. Rather than long extended stays in depot, the aircraft will be back at its unit in less time. She estimated it will take five to eight years before a proven HVM philosophy can be applied to the whole fleet.

Similar to HVM, Warner Robins is beginning an effort dubbed Maintenance Steering Group 3, for its C-5 depot team. Based on commercial fleet standards, the program focuses on being more proactive during scheduled maintenance.

A sheet metal mechanic with the 561st Aircraft Maintenance Squadron repairs damaged components in an F-15 engine compartment. (USAF photo)

“We will probably see [a C-5] less, but we’ll be working on it more when it comes in,” Wallace said of the new process just getting under way. The C-5 team at Robins will add inspectors, mechanics, and warehouse space. Additional parts will be kept on-site to cut the time spent waiting for the parts pipeline to catch up with reality.

While leading the way on initiatives such as lean operations and AFSO21, the Air Force’s depots are also facing some steep future challenges.

Of Robins’ civilian workforce, 17 percent are already retirement eligible, Peyer pointed out. That figure is similar across the Air Force’s depots.

Due to drawdowns in the 1990s and other factors, a “bathtub” of missing middle managers has appeared in the center’s workforce. This is a dangerous liability for an ALC which is expanding rapidly to meet demands, she said.

As older systems are eventually phased out and newer systems such as the F-22, Global Hawk, and F-35 come into the force, more emphasis will be placed on managing advanced software design and stealth technology in the depot process.

Peyer said the challenge for Warner Robins—and the depots in general—is to prepare for a future force that will be very different from the one flying today. Peyer said that when she came into the service, the F-4 was a labor-intensive aircraft which took up to 60 maintenance man-hours per flying hour to keep in the air.

The F-15 incorporated improvements with diagnostics and maintainer accessibility, helping cut down on maintenance hours significantly by telling maintainers where the problem was located.

Mike Daley, an aircraft sheet metal technician, polishes the interior of an F-15 canopy. (USAF photo by Tommie Horton)

Systems such as the F-22 now use prognostics to predict when a system is degrading—improving some aspects of maintainability even further.

Investments need to be made in the personnel. “Better performance just doesn’t come by whacking people and reducing your force,” Peyer said. It comes through building a more sophisticated system with higher reliability and maintainability, and by making sure the people working on those systems are trained properly.

“These are pieces of metal that someone’s son or daughter is flying in,” Levy said. “They’re going to take it out of here, and go commit aviation. We want to make sure it’s as high quality as possible.”