ALC set to maintain largest engine yet Published Nov. 25, 2009 By Howdy Stout Tinker Public Affairs TINKER AIR FORCE BASE, Okla. -- Tinker officials briefed Under Secretary Alan Estevez this week on plans to maintain the F117 engines that power the Air Force's C-17 transport aircraft. Mr. Estevez, principal assistant deputy undersecretary of defense for logistics and material readiness, received the briefing during a tour of the Oklahoma City Air Logistics Center in conjunction with the annual Tinker and the Primes conference. The ALC is taking on the engine work in a multi-million dollar partnership with engine manufacturer Pratt and Whitney. The engine will be the first mid-sized turbofan and the largest engine to be maintained by the ALC to date. The F117 engine, derived from the commercial engine originally designed for the Boeing 757, is currently maintained by Pratt and Whitney in Cheshire, Conn., and United Airlines in San Francisco. During the past three years, Congress has funded additional C-17 aircraft, increasing the number of engines that will be needing repair. The ALC will help provide capacity for those additional engines. Each aircraft is powered by four F117 engines. There are an estimated 1,000 engines in the C-17 fleet. "We're very interested in this workload," Mr. Hayes said, adding that ALC work on older engines such as those powering the KC-135 tankers is declining, while planned future workloads for the Joint Strike Fighter and KC-X tanker are still a couple of years away. "This fills a nice gap for us." The ALC will provide the skilled work force to maintain the engines. Once fully functional, the shop will employ up to 150 workers in two shifts who will maintain an average of six to 10 engines every month. Under the partnership, Pratt & Whitney will identify repairs needed for each engine and will provide any spare parts necessary to complete the repairs. Under the terms of a $14.1 million contract announced at the end of September, Pratt and Whitney will provide most of the tooling for the new shop being built at the ALC in Bldg. 3001 to maintain the engines. "We expect to have the basic shop done by the end of this month and will be receiving tooling for the next few months," Mr. Hayes said. Pratt and Whitney will deliver the first practice engine early next year. The engine will be used to train workers in the specifics of maintaining the F117 engine. In addition, the shop has applied to be certified for engine repair by the Federal Aviation Administration, a first for the Air Force. The ALC will not actually perform repairs on commercial aircraft or engines, but will hold FAA approval of its processes. "We will be the first FAA-certified engine repair facility in the Department of Defense, building on the 76th AMXG's already successful FAA certification for KC-10 aircraft work," Mr. Hayes said. FAA certification will allow maintainers access to commercial spares and services and will ensure that work done by the ALC on the F117 engine will also meet commercial standards. "Ideally," Mr. Hayes said, "the standard of work done by the ALC shop will be indistinguishable from its civilian counterparts." "Tinker already boasts an experienced and mature workforce", he added. In addition, the largest single user of the C-17 aircraft is the Air Education and Training Command's 97th Air Mobility Wing based at nearby Altus Air Force Base, Okla. The base is the main training center for Air Force and foreign operators of the C-17 aircraft. By the end of production the Air Force will have some 205 C-17s, not counting those flown by Britain's Royal Air Force, the Royal Australian Air Force, Canadian Air Force , NATO and the Qatar Emiri Air Force. South Korea, the United Arab Emirates and India are also planning to purchase C-17 aircraft. There is the potential for the ALC to take on this engine workload as it already maintains a number of contracts with foreign air forces for depot maintenance of parts and engines. The new work moves the ALC into the realm of maintaining larger turbofan engines. Considered a mid-size turbofan, the F117 produces 41,000 lbs of thrust, more than the F135 that powers the new F-35 Joint Strike Fighter. "And the F117 is capable of producing that thrust without an afterburner," Mr. Hayes said. The size of the engine alone will require some new techniques. With only a foot-and-a-half of clearance on either side, the engines will be moved in and out of the building only after hours so it doesn't obstruct the main aisle ways in Bldg. 3001. Also, the engines can only be taken in and out through the building's hangar doors, as it is too large to fit through any of the other entrances. "This guy is a monster," Mr. Hayes said. "It is almost 13-feet across and 24 feet long coming off the aircraft." The new shop will be located near Hollywood and Vine in Bldg. 3001 and extend the length of more than two football fields. Designed from scratch, the new shop features half-a-dozen new overhead cranes with areas allocated for spares, tool trolleys and engine assembly and disassembly. "It's the first full depot activation since the F108 engine in 1992," explains Steve Creek, flight chief for the 547th Propulsion Maintenance Group. The F119 engine was more recent, but did not address test cell capability. Mr. Creek says the shop features the strongest cranes in Bldg. 3001, each with controls sensitive enough for a single worker to lift and stand an engine on end if necessary. "The shop's design is a collaborative effort between Pratt and Whitney and the ALC", Mr. Creek said. "It's very well designed," Mr. Creek said. "We wanted a clean look, state-of-the-art." The size of this engine will give the ALC solid experience for the proposed engine maintenance contracts for the yet-to-be-announced KC-X tanker slated to replace the ageing fleet of KC-135s. The KC-X is expected to be powered by even larger turbofans than the F117. "It takes us to the next step," Mr. Hayes said. "This kind of engine gives us a good idea of what it will take to get there."