MARINE CORPS AIR STATION YUMA, Ariz. -- Two Marines sit behind a panel of what seems like as many switches as mission control at a shuttle launch, and through double-paned glass is the test chamber where another Marine gives a thumbs-up.
The building is suddenly filled with a high-pitched whine as the F402-RR-408B jet engine, used exclusively by the AV-8B Harrier II, fills the air with a thunderous roar that vibrates the entire structure with its power.
The Marine inside the test chamber checks for leaks, ensures he is a safe distance from the exhaust ports, and gives the control center another thumbs-up, signaling them to increase thrust.
The tone of the whine changes as more power is given to the engine.
This is the scene almost daily at the T-10 Test Cell, Building 310 here.
“This is probably the closest an enlisted man gets to flying an aircraft,” said Cunningham.
Every time a Harrier engine is worked on by the power plants division, the engine must be tested for a variety of factors, said Sgt. Bryan Marchman, Marine Aviation Logistics Squadron 13 test cell operator and native of Leander, Texas.
“We do leak checks, test thrust, acceleration, vibration and heat,” said Marchman.
Just like any other place jet engines run, the day starts with safety, said Sgt. John D. Park IV, MALS-13 test cell operator and native of Sacramento, Calif.
The first order of business is a foreign objects and debris walk to ensure nothing can get sucked into and damage the engine. Regulation states that the floor of the test cell be washed each week, but the Marines working there take it one step further and wash it every day, said Park.
The daily inspection takes 45 minutes every morning if everything goes well and sometimes longer if there is a problem that needs correction, said Marchman.
“We take extra steps to ensure the safety of the facility because if the engine gets (damaged) while it’s here, then it creates extra work for power plants, and they just got done working on that engine and sent it to us,” said Marchman.
The test cell supports all of the Harrier squadrons on station and then some, said Cpl. Matthew R. Cunningham, MALS-13 power plant mechanic, test cell operator and native of West Palm Beach, Fla.
“We support other squadrons because the Harrier community is so small they might not have the manpower (at that time),” said Cunningham.
The test cell supports detachments and deployments to Al Asad Airfield, Iraq, Marine Corps Air Station Cherry Point, N.C., MCAS New River, N.C., MCAS Miramar, Calif., the Marine Corps installations in Japan and the Marine Expeditionary Units as well, said Cunningham.
All of the test cell operators started out as power plant mechanics and volunteered for extra training to become test cell operators. Power plant mechanics are selected as test cell operators specifically because they know the engine already and can perform minor maintenance to fix problems they find during testing, said Park.
While the job isn’t glamorous, as they leave work consistently with oil stained hands and uniforms, the test cell operators take comfort in knowing the specialized job they perform is vital to the operation of the Harriers on the air station.