442 MXS Phase Dock pioneers field-level repair of valve, saves tens of thousands of dollars

  • Published
  • By Master Sgt. Bob Jennings
  • 442d Fighter Wing Public Affairs

“I think a lot of people are afraid of venturing outside what they think they’re allowed to do,” said Master Sgt. Christopher Yates, the 442d Maintenance Squadron’s phase dock coordinator, November 9, 2021, in the A-10 phase dock on Whiteman Air Force Base, Mo.
It takes a considerable amount of effort to keep a 40-plus-year-old pig flying. Which is why, every 600 flying hours, A-10 “Warthogs” undergo what’s called a Periodic Phase Inspection. During phase, the jet is pulled apart, nearly every component is inspected for functionality and serviceability, and then it’s put back together.
One of those components, at least for the 442d Maintenance Squadron’s Phase Dock, is the football-shaped engine bleed air shut-off valve. The football valve, as its name implies, controls the flow of bleed air from the engine to the air conditioning pack to be used in cabin pressurization, climate control, and canopy defogging. 
Like the jets they’re attached to, however, the valves are aging. Typically, when a football valve fails, it’s removed, replaced, and turned in to supply to be shipped off to Tinker AFB, Okla., for repair. When the depot facility has supply issues themselves, though, things can start to get backed up.
“There’s nothing technically saying ‘hey, you guys need to check these valves,’ “ Yates said. “We do it for preventative maintenance during phase.” During their inspections, the phase team found a rash of valves either beginning to fail, or failing outright.
As the phase dock chief, it’s Yates’ job to provide the flightline with serviceable jets in a timely fashion. With the strict maintenance schedule required to keep the Hawgs in the air, there’s not a lot of wiggle room in the timeline. So, when a valve’s delivery date got pushed back multiple times – and it was only one of 49 on backorder throughout the Air Force – Yates finally decided to take a different approach.
He cracked open the books, specifically Technical Order 00-25-195, AF Technical Order System Source, Maintenance, and Recoverability Coding of Air Force Weapons, Systems, and Equipments, where he determined that the valve was, in fact, reparable at the field level, dependent on equipment availability.
“There are some limitations,” Yates warned, “and I wouldn’t just suggest anybody go out and start yanking stuff apart without backing themselves up with data.”
After taking a few valves apart, and with the help of engineering drawings, Yates discovered different reasons for failure, but the two most common, a bad spring and corrosion caused by years of extremely hot, moist air passing through, were easily within the capabilities of the phase dock to correct. 
“It’s a robust component,” Yates said. “Very robust. It’s just that no one’s ever taken the time to investigate what would it take to just clean it, and put it back into service.”
“The biggest problem locally has been like, ‘Who says you can do that?’ Well, the book says I can,” Yates said, before reading out the exact section in the manual that gives authorization for limited repair of the valve at the field or organizational level.
Repairing valves, however, is not Yates’ endgame. “I think I’ve estimated between six and eight hours to go through one completely – to take it apart, clean it, and put it all back together.”
Yates’ plan is to first try to teach others not only to repair the valve and save money – each valve costs approximately $20,000, plus an extra $6,000 for expedited shipping – but also to eventually set up an Air Force Repair Enhancement Program to perform component repairs without the need to wait on the supply system.
Yates’ repair of the valves not only saves valuable time and money, but it also helps to keep the Reserve Citizen Airmen of the 442d Fighter wing ready to attack, defend, support, and sustain.