ISO dock keeps C-5 fleet in check Published Dec. 7, 2015 By Senior Airman William Johnson 436th Airlift Wing Public Affairs DOVER AIR FORCE BASE, Del. -- The 436th Maintenance Squadron Isochronal (ISO) Maintenance Dock helps keep the largest aircraft in the Air Force inventory, the C-5 Galaxy, in the air to deliver cargo, combat equipment and humanitarian relief supplies to anywhere in the world whenever called upon. In an effort to maximize the lifespan of the C-5 fleet, the aircraft goes through a series of inspections that vary in recurrence and depth; pre-flight, home-station check, Maintenance Steering Group-3 Minor, MSG-3 Major and Programmed Depot Maintenance. All C-5 aircraft in the inventory undergo an eight-year scheduled maintenance timeline through the MSG-3 process. The cycle for these inspections goes as such: Programmed Depot Maintenance, Minor ISO, Major ISO, Minor ISO then starting back at PDM. Each inspection is two years apart and continues for the lifecycle of the weapon system. Dover AFB has the only facility in the Air Force that is able to conduct Major ISO inspections. The MSG-3 Major inspection takes approximately 55 days, depending on what services and repairs the aircraft needs. Maj. James Wall, 436th MXS commander, said at the 55-day rate, the ISO dock is able to turn out nine aircraft a year, which keeps the entire C-5 fleet on its eight year maintenance cycle. During an ISO inspection, aircraft maintainers strip down the C-5 looking for any deficiencies, faults, cracks or any other problem in every system and of the aircraft. First Lt. J. Spada, 436th MXS maintenance flight commander, said it is critical that all maintenance is performed right the first time during a major-level inspection. If something is missed during a major-level inspection, the aircraft could suffer until it undergoes another major- or depot-level inspection. "The biggest difference between a major and a minor inspection is the amount of depot-level work that is done during the major inspection," said Spada. "We also check up on critical systems that have a high failure rate and perform a lot of preventative maintenance that has shown, if done in a four year interval, it will help the aircraft become more reliable as it progresses on." With so much riding on these major inspections, there is little-to-no room for error. That is why Wall said it takes a special type of maintainer to work in the one-of-a-kind facility. "As far as C-5s go, the most industrialized maintenance facility in the Air Force I would argue is the ISO dock here," said Wall. "The technicians that conduct the major ISO inspections are of a higher caliber maintainer and they have to be because of the environment that they are working in." Tech. Sgt. Kevin Taylor, 436th MXS ISO dock floor chief, is one of those elite maintainers and helps recruit Airmen to work in the ISO dock. Taylor said typically C-5 crew chiefs are recruited for the job, but there are a host of other specialties that Airmen fill. "There is more complicated maintenance in a major inspection than you'll find anywhere else at a field-level facility," said Taylor. "Because of the technical difficulties that we see during a major ISO, we have to vet and obtain only the best specialists and crew chiefs to work in this dock." Approximately 30 Airmen from the 436th MXS have also been assigned to work at the 439th Airlift Wing at Westover Air Reserve Base, Massachusetts. The integration of the two wings began in 2008 as a measure to assist the 439th MXS with minor ISO inspections of the entire Air Force's C-5 fleet. "Prior to 2008, the average Westover minor ISO inspection took 40-plus days to accomplish," said Master Sgt. Peter Michaud, 436th MXS Operation Location Alpha detachment chief. "With the integration of the 436th MXS OLA, 439th MXS and the advent of the MSG-3 process, the ISO was reduced by 26 days down to an 18 day average." With recent upgrades to the C-5M Super Galaxy, the Air Force projects having C-5s in their fleet beyond 2040. However, it will be the responsibility of the Airmen in the 436th MXS ISO dock to ensure the C-5s see that date.