Process improvements part of C-130 propeller shop's success Published June 12, 2009 By Wayne Crenshaw 78th Air Base Wing Public Affairs ROBINS AIR FORCE BAE, Ga. -- The C-130 propeller shop has been at Robins for a long time, but they are still finding ways to do things better. In the past couple of years the shop has made equipment and efficiency improvements that have reduced flow days, which is the time it takes to refurbish a full propeller assembly, from 45 days to 38. Although a propeller might seem like a simple part of an aircraft that wouldn't take much maintenance, the assembly goes through a several-step process that includes disassembly, cleaning, grinding, polishing, reassembly, balancing and testing. The primary purpose of the work is to prevent corrosion. It used to be that those operations were spread throughout the huge building shares with other shops. About two years ago, the prop shop operations were consolidated into one area to reduce the time it takes just to move the blades and parts from one area to another. "In the old process we had 7,000-plus linear feet that the blade would actually travel," said Flight Chief Chris Barkley. "Now we have that down to about 800 feet." Automation has also not only sped up the process, but reduced the physical demands on workers. The first step after the disassembly is cleaning the blades and stripping the black covering on their lower end. At one time that was done with chemicals, but around the early 1990s the shop started using high-pressure water. Workers used a handheld wand to spray water at about 15,000 pounds per square inch. Consider that a top-line home pressure washer runs about 3,000 PSI. "We used to have people standing there all day long going back and forth and back and forth with a wand that was 15,000 PSI," Mr. Barkley said. "You can imagine how it would hurt their backs." About a year and a half ago, the shop installed a machine called an aquamiser to do that job. The blades are now put into an enclosed area where the machine does the same thing at 30,000 PSI. For further corrosion prevention, the shop had at one time used handheld grinders to polish a blade. That took about 45 minutes and also put physical stress on workers. But last year the shop installed an $800,000 robot that picks up the blade and runs it over a belt grinder. That reduces the process to about 17 minutes. Propeller mechanic Michael Lawhorn was operating the robot when Mr. Barkley gave a tour of the shop last week. Mr. Lawhorn said he has been working at the shop for eight years, and he likes the fact that job duties are rotated regularly. "I'm in a shop where we've got a different thing to do every day," he said. A propeller assembly includes four blades and the barrel housing that attaches to the aircraft. Each assembly costs $189,000, and must go in for maintenance approximately every 5,000 flying hours. The assemblies are shipped around the world, not just for the C-130s maintained at Robins. Although the shop tests the integrity and balancing of the assemblies, it's the shops where the installation is done that will place them on a machine for run up before the installation. Carl Nelson, the deputy flight chief, said the shop's 70 employees are hardworking, dedicated people who practice the wingman concept. "This whole flight is real family oriented," he said. "If somebody is down, or a family member is down, they are there for each other."