PEASE AIR NATIONAL GUARD BASE, N.H. -- Engine mechanics with the 157th Maintenance Group completed the first full replacement of an auxiliary power unit on a KC-46.
“This is a big milestone,” said Col. Brian Jusseuame, the commander of the 157th Maintenance Group. “APUs play a very important role on the aircraft, and this is the first on a KC-46 Air Force wide.”
An APU is an engine in the back of the KC-46. It provides power to start the main engines and generates electrical and compressed air power to run the heating, cooling, and ventilation systems prior to starting the main engines. In the event of engine failure during flight, it can be used for either electrical power or bleed air to restart the engines.
The unit inside the KC-46 at Pease was vibrating excessively and causing the duct work to shake.
“We had been troubleshooting an error message that plagued us for many months,” said Maj. Alex Morris, the Commander of the 157th Aircraft Maintenance Squadron. “The mechanics worked through every possible part of the aircraft, and this was the last option.”
The team replaced the APU with the same model. They used fishing pole lifting equipment and a small crane to extract the first engine and keep it suspended while they transferred parts to the new unit.
“We’ve had training on how to do it, but this is the first time we’re doing a full install,” Master Sgt. Dustin Bugado, an engine mechanic with the 157th MXG. “We’re learning lessons and shortfalls by going through the entire process.”
Outside of a training exercise at Altus Air Force Base, this is the first time a brand-new power unit was taken from supply and installed by Air Force personnel. The team of Airmen said the installation took longer than initially planned but they enjoyed the hands-on success.
“Doing anything new with this aircraft is exciting and challenging,” said Bugado.
“Working on the KC-46 is also really different from the KC-135,” he added. “In a 135 there were notes on everything. Anything that could’ve broken had already been broken and someone worked out all the things that could go wrong. By the time we were fixing the planes, that process had happened 100 times over. Now we’re the first ones.”
The suspected faulty engine is being sent to Honeywell for further inspection and the new APU is up in the KC-46 flying over New Hampshire.
“It’s a notable task,” said Morris.
“I’m happy to say the aircraft has not shown any more of the faulty symptoms and I’m especially proud of the mechanics,” he said. “They worked through every option and completed the huge lift efficiently and safely.”