Maintaining Flight Attitude

The U.S. Air Force is transforming depot maintenance at the technician level, tapping vendor support to produce higher output quality and efficiency.

by Karen E. Thuermer, MLF Correspondent

In the area of highly skilled work force sustainment, Air Force Materiel Command (AFMC) depot maintenance is focusing on tools to recruit, train and retain top-notch personnel and provide them the tools to continue world-class support to the warfighter.

In the area of new innovative depot maintenance technology, its infusion is being accomplished through a process in which technology needs are identified and documented in technology road maps. These road maps serve as the foundation of sustainment technology investment strategy by focusing on the research, development, test and evaluation of game changing technologies. The road maps also provide common solutions for multiple customers and measurable improvements to sustainment capabilities.

As an example, technologies are being pursued, which provides the ability to assess the structural health of aircraft prior to inspection, thereby minimizing disassembly of the aircraft, getting replacement parts just in time for installation and significantly reducing the time the aircraft spends in maintenance. Another example involves technologies capable of reducing the time required to paint and repaint an aircraft from days to hours. Once technology requirements are identified in the road maps, they are prioritized and recommended for funding as a part of the annual budgeting process.

“AFMC is committed to providing stateof- the-art, environmentally compliant, efficiently configured, and properly equipped facilities to support existing and projected depot maintenance workload,” said Joanne Rumple, AFMC spokesperson. “This commitment has required us to increase our investment from approximately 3 percent of revenue each year to a minimum of 6 percent,” she said.

PROGRAMMED DEPOT MAINTENANCE, KC-135

In the wake of DoD’s postponement of the aerial refueling tanker rebid, the Air Force prepared to review maintaining the KC-135 fleet for extended service life. Today the KC-135 fleet’s projected retirement date is 2040.

“Operating an aircraft fleet for 70 to 80 years is unprecedented in aviation history,” Rumple said. “Maintaining an operationally safe and effective KC-135 fleet requires continued vigilance, effort and resources.”

Numerous studies/analyses have been conducted over the years on the viability of the KC-135 fleet. A teardown inspection program has been established for FY 2009–2015 for the purpose of updating analyses critical to proactively managing structural risk.

This program will provide insight into the condition of the fleet and guide future maintenance actions. Findings from the teardown inspection program have the potential to reduce the uncertainty and better define risk and the associated costs of operating the fleet to 2040.

In 2007, the Boeing Company was awarded a 10-year, $1.1 billion U.S. Air Force contract to continue providing programmed depot maintenance (PDM) for the nation’s KC-135 Stratotanker fleet. Currently, however, Boeing is completing KC-135 PDM work under a bridge contract pending the outcome of a Court of Federal Claims decision to rebid the contract award. Since its initial KC-135 PDM contract award in October 1998, Boeing has completed scheduled and unscheduled maintenance on more than 185 aircraft. Unscheduled maintenance comprises about half of the PDM work.

“Boeing’s focus is to be a solution provider for the Air Force,” remarked Pat Leahy, Boeing’s KC-135 program manager. “We bring in aging aircraft, perform detailed inspections, repair and refurbish the aircraft and deliver them back to the warfighter.”

Scheduled PDM, which includes depotlevel inspections, repairs, maintenance, modifications, repainting and supply chain services, is performed every five years on the active KC-135 fleet. Whereby it previously took 300 to 400 days to perform the service, today Boeing’s average turnaround of an aircraft is 170 to 195 days with an average 10 to 12 aircraft in house.

“Our process is most efficient when we have a full complement of aircraft in house. We are capable of bringing our turnaround days down to 145, provided we have a consistent or steady flow of aircraft for our teams to work on,” Leahy explained.

The PDM process begins when an aircraft is flown to the depot in San Antonio where Boeing employees disassemble, defuel and remove all major components such as the outer wings, flight control surfaces, vertical tail, engines and landing gear. “We also remove all of the paint on the aircraft’s surface to see the condition of its skin,” Leahy said.

All parts are tagged, documented and kitted to maintain a record of what aircraft they came off of and in what order so that they can be reassembled back onto the aircraft later in the process. “Those parts go to one of our back shops where they are cleaned, painted—and if necessary re-identified,” he explained.

FOUNDATION UP

Air Force maintenance protocol dictates that all aircraft undergo a periodic “shakedown,” meaning inspectors thoroughly inspect the aircraft and record all findings. Among the common problems found are corrosion, wiring defects and issues with the aircraft’s overall condition. The aircraft is then passed to another team that performs any required maintenance.

As part of Boeing’s lean manufacturing philosophy, the process entails eight “cells” of mechanics with the aircraft moving or “pulsing” to a subsequent cell position every 10 or 11 days. Since the aircraft comes to the mechanic, versus the mechanic going to the aircraft, all the tools are laid out in each cell for each specific job much like the surgical tools of a surgeon. Mechanics do not have to run around looking for tools, pieces and parts.

“The aircraft pulse through this cellbased assembly line,” Leahy explained. “The pulse drives our performance, since we know how many hours of scheduled work are in each cell.”

Each maintenance team is staffed with enough people to complete that amount of scheduled work. “They complete the work and move the aircraft to the next station or cell where the next team takes over and performs their tasks,” he said.

The aircraft continues to pulse through each cell, and when it reaches Cell 7, all final work is done on the aircraft such as installing the main landing gear and final door close ups. At that point, Boeing’s internal customer, the Defense Contract Management Agency (DCMA), conducts a quality inspection of the aircraft.

“We work with DCMA to ensure the aircraft is ready for the final cell, Cell 8,” said Leahy. “At this point we look at the critical jobs like safety wiring and closing up of cavities for fuel bladder installation.” At Cell 8 the aircraft goes to the paint/ repaint hangar, where it is painted or repainted and Air Force markings are put on.

“We then turn the aircraft over to our local aircrew that performs flight testing,” Leahy said. “The flight test takes about 3.5 hours. Once flight operations are completed, the aircraft is ready for delivery status.” Although the maintenance process is seamless, along the way Boeing uses a series of suppliers to refurbish major components and supply new parts.

CONTRACT LOGISTICS SUPPORT

The Air Force is addressing the importance of training properly skilled maintenance personnel through an emphasis on simulation. AAI Corp., an operating unit of Textron Systems, a Textron Inc. company, operates its AAI Services Training and Simulation group in Charleston, S.C. That group is responsible for providing training modifications and logistics for C-17, F-22 and F-35 maintenance training devices.

“All three projects are focused on organizational- level maintenance training,” said Paul Mueller, vice president of the group. “Whereby airmen are maintaining equipment on the frontline, we provide the equipment that allows them to learn their skills.”

To do this for C-17 and F-22, the group builds full-scale replicas of aircraft parts on which airmen can train. “The C-17 devices can be used by the Air Force to train all the way up to actual certification,” he stated. “Our goal is to have the trainers current with the aircraft.”

The Air Force uses this equipment to keep their maintainers proficient in the configuration of the airplane as well as transition their maintainers from other airplanes to the C-17.

Since it is critical for the Air Force to have these aircraft back up and running quickly, AAI’s goal is to train maintainers so they can be on the flight line ready to interface with new complex weapons systems in a timely fashion and with a minimum turnaround time. Maintainers working on F-35 and F-22 aircraft use portable maintenance aids (PMAs) to interface with the aircraft to run diagnostics.

“We want to make sure that the diagnosis of the systems is familiar,” Mueller said. “Our training devices are sufficiently complex to allow the airmen to interface with the on-board diagnostic and self-test system like they would on the airplane.”

AAI is building equipment that allows the airmen to hone their proficiencies or gain that additional knowledge about how PMAs work, what level of control it has over the airplanes, and how to do diagnostics using this aid.

LEGACY UPDATING

The Air Force requires logistics and air mobility solutions for legacy aircraft weapon systems, including its aging aerial refueling tanker fleet. Northrop Grumman provides these solutions through a contract with its technical services division. Northrop Grumman’s Technical Services sector is providing the Air Force with logistics and sustainment air mobility solutions for its legacy aircraft weapon systems, to include the aging aerial refueling tanker fleet.

Northrop Grumman Technical Services engineers are strategically located at a number of Air Force MRO depots throughout the United States and around the world providing sustaining engineering support for various weapons, avionics and defensive systems. The company is continuously working with its Air Force customers to provide them with new and innovative technology-based solutions allowing them to be more responsive to the warfighters and accelerate the maintenance turnaround on aircraft, while increasing operational availability.

One such innovative technology for sustainment is a rapid reconfigurable dynamic test stand (DTS) designed by Technical Services capable of supporting a host of C-130 variants as well as rotary wing aircraft. The DTS helps Northrop Grumman Technical Services accelerate a number of aircraft upgrades and perform comprehensive laboratory testing, which provides significant savings in follow-on flight testing. Larry Wingate, Northrop Grumman’s director fleet sustaining engineering, pointed out that this technology has and continues to support most of the special operations forces aircraft.

Wingate also highlighted Technical Services’ role in aircraft maintenance, repair and overhaul. “From a logistics standpoint, we develop the tools to assist in the aircraft overhaul function from the day it is received to the day it is released,” he said.

One of the logistical decision tools that Wingate attributes to saving the Air Force millions of dollars is the Enterprise Analysis and Cost Optimization System (EACOS) and reliability centered maintenance tools (RCM). These fleet-sustaining, engineering optimization tools allow one to optimize the repair cycles by looking at more than just the failed parts that might go into circuits, subsystems or engines. Around for some time, EACOS and RCM are particularly useful in alerting MRO operators of components that might need replacing while repairing or replacing other components on an aircraft.

To ensure a highly skilled MRO work force, Northrop Grumman has implemented an engineering utilization program. One of the key elements of this program includes a companywide database of all employees with engineering skills, making it possible to quickly respond to Air Force needs.

INTEGRATED SUPPORT

Among other programs, the Air Force is teaming with L-3 Vertex, a division of L-3 Communications, in providing contractor logistics support (CLS), offering full-spectrum maintenance and supply operations supporting fleets of aircraft and related systems; aircraft parts services, providing supply inventory system management for aircraft replacement parts, including worldwide procurement and distribution working with thousands of active suppliers; and contract field services (CFS) for DoD/all service branches and other federal agencies.

CLS, in particular CLF, employs fast, mobile teams to provide temporary and long-term labor support for a variety of technical services needs: maintenance and repair, depot services, inspections, modernization for contingency support for aircraft, vehicles, weapon systems and other equipment. Teams of any size or duration are available worldwide on short notice.

In addition, L-3 Vertex offers depot operations services involved in aviation installation and retrofit, aircraft condition inspection, interior refurbishment, major aircraft rework, crash damage repair, strip, painting and structural repair.

On September 25, 2008, L-3 Communications, the prime contractor for the U.S. Army and Air Force Joint Cargo Aircraft (JCA) program, presented the first C-27J JCA to the joint program office on schedule and on budget. The aircraft is the first of 78 planned to be delivered to the DoD.

PARTNERING FOR TRANSFORMATION

Air Force air logistics centers are also working with Honeywell to achieve several major transformation goals.

“We are working with the ALC centers of industrial excellence such as the Ogden ALC for secondary power to bring work currently being done outside back into the depot,” stated Kurt Meister, Honeywell vice president, Lockheed and Air Force programs. This is directly in support of Title 10, Section 2466, Percentage Limitation on Depot Workload—more commonly referred to as the 50/50 rule.

Honeywell partnerships also support Title 10, Section 2474—the public-private partnerships that allow the government to partner with industry to increase usage of underutilized facilities or equipment in support of production or maintenance.

“In general, our public-private partnerships maximize capacity, fully utilize the depots’ highly skilled work forces, reduce costs, and increase availability and warfighter readiness,” Meister explained. “By offering industry best practices to enhance efficiencies of the sustainment infrastructure, additional weapon systems can be added.”

The Honeywell partnerships also provide an avenue through which the Air Force can bring new technologies and products earlier into their sustainment infrastructure. For example, Honeywell is currently working with Lockheed Martin and the Ogden ALC on a core organic capability for repair of the Air Force fifth generation fighters.

“Honeywell is in the process of standing up depot repair capability of the F-22 auxiliary power generation system,” Meister said. “And we look to work closely with the Air Force in the future, exploring how to bring the F-35 power thermal management system into the Air Force’s organic sustainment infrastructure.

Honeywell is also currently working with several OEM primes as they prepare for the upcoming KC-135 Block 45 upgrade program. Honeywell is investing R&D resources to optimize the update of this core system so it addresses the KC-135’s present and future needs—while addressing the current and future needs of several additional mobility and tanker platforms. Honeywell is also pursuing the recently announced KC-10 CNS/ATM upgrade program aimed at upgrading the KC-10 to meet future airspace requirements—as well as sustain this platform throughout its service life.

FUNDING

To help jump-start its maintenance transformation investment plan, the Air Force funded an additional $150 million per year between FY 2004 and FY 2009. These infused funds have helped tremendously in the modernization of AFMC’s depots. As an example, a new three-bay aircraft hangar project at Tinker Air Force Base will allow greater workload flexibility due to its ability to accommodate existing and future aircraft. It also provides reduced flow time by eliminating wasteful aircraft movement.

“To ensure that our infrastructure remains properly sized, we review future weapon systems and modification programs well before they are fielded,” Rumple added. “This helps us shape our investment strategy. We also review legacy system attrition plans so we can properly divest/modify existing capacity as necessary.”

Funding from various sources is leveraged to execute high priority technology projects. “Our depots and field operations champion the most promising technologies and support their migration from concept demonstration to full implementation,” said Rumple. “This collaborative partnership between all stakeholders facilitates technology insertion into maintenance operating practices.” ♦