Propulsion Airmen make noise in the 'Hush House'

by Senior Airman Shawn Nickel
354th Fighter Wing Public Affairs

10/8/2013 - EIELSON AIR FORCE BASE, Alaska  -- "If we close those doors, the building will implode," yelled Tech. Sgt. Joshua Baker as the engine from an F-16 Fighting Falcon sucked freezing air into the "Hush House" through tall slats on the walls.

The thrust demonstrates the maximum power fighter jets from the 18th Aggressor Squadron use while hosting RED FLAG-Alaska several times a year and intensely training in between.

"The pilots force these engines to the limits, then after they reach a certain point, we get to take them apart, rebuild and make sure they can safely take them to the limits again," said Baker, the test cell flight chief from the 354th Maintenance Squadron.

Airmen from the 354th MXS propulsion flight rebuild the engines to maintain Eielson's missions. With an average of nine engines a year and a record of 13, the self-proclaimed "World's Best Propulsion Flight" is always on the move.

From the beginning of a project to the end can take days to months depending on the availability of parts and the condition of the General Electric F-110-100 engines they maintain. Once every nut, bolt, wire and tube is in place, it's time to mount the engine in the "Hush House" and put the pedal to the metal.

"It's awesome to see days of work come together and feel the airpower we're part of," said Staff Sgt. Daniel Kaufman, 354th MXS dock chief, as the engine rumbles the entire building.

"Every time we get to test an engine, it makes all the long hours and hard work with a wrench worth it."

As the engine starts, air is pulled into the "Hush House" through flaps on adjacent walls that resemble gills on a fish. Because of the force of the engine, instruments measure air pressure to ensure the walls don't implode, said Kaufman.

"This building is essentially portable, giving us the ability to have it packed up and transported anywhere in the world, but it's also specially designed to keep most of the noise inside," he said.

After the outside air is brought to negative temperatures from the wind chill, it is combusted by the engine running full throttle and forced out the exhaust tube behind it. The specially designed tube dampens the sound using corrugated metal panels filled with a material resembling steel wool. As the now hot air is projected upward, it rumbles the surrounding buildings, yet much quieter.

"This process isn't just to make noise, it's to make sure we did our job right rebuilding the engine," Baker said. "After the check is complete, everything is inspected once more before we place the engine back in the Aggressor."

The camouflage jets from the 18th AS wouldn't be able to take off safely without the expertise of these propulsion experts and Baker assures every time a pilot gets in the cockpit, they can be confident every part and piece of that engine is in excellent order.

"Our job is fun, but it's also extremely important," he said. "Every one of us loves to push that throttle forward in the test cab and watch a perfect test, just knowing that engine is going to make a difference somewhere soon."