by Senior Airman William Johnson
436th Airlift Wing Public Affairs
12/7/2015 - 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
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
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
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.