NIAGARA FALLS AIR RESERVE STATION, N.Y. -- For over 60 years one aircraft has been the core aerial refueling capability for U.S. operations around the world.
“Every day we make history keeping these aircraft in the air because of the men and women of the 914th Maintenance Group,” said Chief Master Sgt. Patrick Martin, 914th Maintenance Squadron Superintendent, proudly.
That aircraft he is referring to is the Boeing KC-135 Stratotanker, operating in the U.S. Air Force since 1957. The KC-135 replaced the propeller-powered KC-97 tankers, which could no longer keep up with the jet fighters and bombers. The aerial refueling aircraft, initially tasked with refueling strategic bombers, was used extensively in the Vietnam War and later conflicts leading to Operation Enduring Freedom and Iraqi Freedom.
Although the KC-135 has been around for many years it is still not the oldest aircraft in the U.S. Air Force fleet. The B-52 Stratofortress long range bomber and the U-2 Dragon Lady high altitude reconnaissance aircraft have been operating since 1955 while the Cessna 180/182/185 has been operating since 1952.
The longevity of the aircraft most likely is a testament to the manufacturer and the maintenance crews that keep them going. A good maintenance program is key for success, but as far as an aircraft is concerned, 63 years and millions of flying hours would be considered outstanding by most people. The oldest tanker at Niagara was built in 1957. The 914th ARW has been flying and maintaining KC-135R Stratotankers since mid-2017.
Part of what keeps the KC-135R at Niagara flying safely is the ISO Dock Inspection. ISO Dock coming from the word isocronical which is a calendar inspection, but in the case of a KC-135 it is a calendar plus flying hour’s inspection. Every 24-months the aircraft gets a complete top to bottom inspection and repairs are made if required.
Staff Sgt. Joshua Carter, 914th Maintenance Squadron, ISO Dock inspector, explained the process.
“This is not the only inspection for the aircraft. There’s through flights, pre-flights, a 12-month inspection, 24-month inspection and there’s a variety of inspections for all sorts of the specialty career fields that work on this aircraft, but this is the big one, the 24-month or phase inspection.”
He stressed that this inspection is mainly conducted to identify any maintenance issues or maintenance discrepancies. Things that can be identified and foreseen to keep the planes flying instead of having unscheduled maintenance.
Carter explained the types of discrepancies and their priorities.
“I’m going to use some basic terms for simplicity. The aircraft has a couple of different levels that we use on aircraft forms. So, some things might be like; the coffee pot is not working on the aircraft, which is something that doesn’t affect the safety and flight of the aircraft.” He also added, “There are some things that are middle ground like, we need to pay attention to this, but it still doesn’t affect the flight. Then we have other things that we call red X’s. Those affect the flight and we want to get those fixed and fixed right so we can get it back out to the flight line so the flight line guys can maintain the aircraft.”
There are a number of personnel involved in the maintenance of these planes and are broken down to stages: ISO Dock, flight line, and all of the specialty shops, engine troops, hydraulic troops, electrical, sheet metal, communications, navigation.
“All of these troops come together to this one process,” said Carter.
Out on the flight line, the crew chiefs prepare the aircraft, called pre docks; opening up floor boards, doing engine runs with all their check inspections. The tanker is then towed in and washed completely. The next step is to de-panel, removing panels and that is the start of the inspection phase.
“From there we identify all the maintenance issues and discrepancies. We’ll go ahead and order parts if required. If there are repairs, some are done locally. We have all of our parts and we fix it and then put it back together. Others on a much larger scale that can’t be handled at this base will be repaired at a major maintenance facility,” said Carter.
“We take it outside once repairs are made and do a post dock. That’s where we do all of our operations checks, making sure that everything we did works properly,” explained Carter.
Chief Martin, explained there are over a dozen air force specialty codes (AFSC) involved in the ISO process.
“There’s a team of forty to fifty professional maintenance personnel inspecting, repairing, or replacing components on the aircraft which can take anywhere from forty to sixty-five days.”
“This is something that is done fleet wide with the KC-135s. Every two years, the tanker is scheduled for a periodic inspection process. We will rip this airplane apart and inspect it, mostly for corrosion which is a big thing we are finding on this aircraft after 60 years of service,” said Martin.
Lt. Col. Albert Knapp, 914th Maintenance Group commander, boasted that his ISO dock team has been able to find some of the toughest problems these planes encounter.
“They find corrosion, cracks and dents, bad control surface cables, twisted tubing, faulty wiring, and corroded trunnions (cylindrical protrusion used as a mounting or pivoting point). They find and fix things others have overlooked and haven’t fixed – after we have worked on them, I am confident that our pilots are flying the best maintained fleet in the force – bar none.”
Every maintainer has the opportunity to be a part of this process.
Staff Sgt. Carter explained, “Everything that we do is a potential training moment for our new trainees who love to work on the aircraft, move things, see the flight controls, launch the aircraft. It’s very exciting once you catch that bug. And it’s very exciting for us as trainers to see this within our younger Airmen.”
“I’m super proud of everyone that comes out here every weekend and every day of the week. We’ve come leaps and bounds since the conversion. Everybody in maintenance squadron, AMXS, and the group to make this process what it is today,” said Chief Martin.
The KC-135R models are expected to continue service until 2040. It is not known currently whether Niagara will continue this mission or assigned a newer airframe such as the Boeing KC-46 Pegasus aerial refueling aircraft, but the ISO inspection is vital to keep the 135s flying safely until then.