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100th ARW conducts first USAFE KC-135 hot-pit refuel

  • Published
  • By Karen Abeyasekere
  • 100th Air Refueling Wing Public Affairs

Airmen from Royal Air Force Mildenhall completed the first hot-pit refuel of a KC-135 Stratotanker in U.S. Air Forces in Europe command history, Jan. 8.

“Hot-pit refueling” is another name for an engine-running refuel while the aircraft is grounded. This type of refueling is already performed on airframes such as the CV-22 Osprey, but until September 2020, had never been recorded on checklists or technical orders as having been performed on a KC-135.

“Hot-pit refueling is a capability we are building to increase our survivability on the ground and increase the amount of gas in the air,” said Chief Master Sgt. Nicholas Tonino, 100th Maintenance Group chief enlisted manager. “This capability will absolutely save time while securing persistent operations by significantly reducing generation times. Our Airmen keep improving our capabilities.”

The running engine provides power to the jet and additionally acts as an air source, so when recovering or launching out of an austere environment, the aircrew have a reliable air source to restart the remaining engines immediately after ground refuel is complete. This allows the aircraft to take off in a shorter time.

The hot-pit refuel turned the refueling process from a four to six-hour ground operation to roughly one hour.

This innovation came directly from Capt. John Della Pia, a former 351st Air Refueling Squadron pilot and chief of squadron tactics, who recently changed duty stations, leaving RAF Mildenhall before getting to see his work come full circle.

Della Pia’s research and findings provided the backbone not only in RAF Mildenhall’s first-ever hot-pit refuel, but also in establishing procedures for the very first KC-135 hot-pit refueling in history, which was accomplished at Al Udeid Air Base, Qatar, by the 379th Air Expeditionary Wing.

It was during Della Pia’s time at the Tanker Weapons Instructor Course at Fairchild Air Force Base, Washington, that he came up with the idea of hot-pit refueling for KC-135.

“During the course, we’re required to write a graduate-level paper, and my topic was tanker turn times and minimizing them,” he said. “We’re in the business of air refueling and we often face a limiting factor of time constraints while on the ground. I decided to work out how we could tackle that tactical problem, which has operational, and even strategic affects, just providing more fuel while airborne and on any given day.”

As part of his research, Della Pia investigated how the usual four to six hours spent on the ground could be minimized while maintaining reliable power and air from the engines.

“It takes four hours for maintenance to perform their preflight inspections, ready the jet for refuel, then two hours for aircrew to run their checks and get ready for the next mission,” he explained. “As part of my research, I wrote draft procedures not only for aircrew, but also maintenance and fuels Airmen.

Della Pia added that refueling procedures on the ground are still the same, whether using pipes via a hydrant, or a fuel truck, but now the number-one aircraft engine will be running during the process.

“This will minimize the amount of maintenance and time-consuming inspections. Previously, there were no precedents for this procedure with the KC-135,” he said.

Della Pia’s leadership understands how vital the hot-pit refueling is to both RAF Mildenhall and the U.S. Air Force, as a force multiplier which reduces aircraft turn time by 83%.

“Without fuel, our capability to sustain global power, vigilance and reach is greatly reduced. As Gen. Charles Q. Brown, Jr., Air Force chief of staff, stated, ‘We have to accelerate change, or lose,’ and hot-pit refueling is an innovative step to help ensure we maintain a competitive advantage,” said Col. Van Thai, 100th Operations Group commander.