Local residents are spared much of the ear-throbbing noise produced when Fleet Readiness Center Southeast, Jacksonville, Fla., conducts out-of-airframe testing to certify the reliability and performance of gas turbine engines repaired at the facility.
Annexed at the far end of Naval Air Station Jacksonville along the St Johns River, the Robert Kemen Engine Test Facility is acoustically treated and aerodynamically designed to reduce the powerful sound waves generated by jet engine combustion during testing.
The walls around the concrete test chamber are 18 inches thick,î said Mark Stogdon, an electronics engineer working at the testing facility. ìWe used to test engines outside in the late ë60s, but the sound carried right across the river. Testing inside is easier, and acoustics are contained. It is considerably safer.
Performance testing in mirror image test chambers is routinely conducted on each engine serviced or repaired at the FRCSE Crinkley Engine Facility. Testing ensures its optimum operating performance prior to returning the engine to Fleet inventory.
Stogdon said about 140 engines are tested at FRCSE each year, and Kemen is the Navyís only depot engine test facility still in use. He said in the “heyday” back in the 1970s, six facilities were to be built, but only one other was constructed at the military depot in Norfolk, Va. It was torn down years later following the depot closures in the mid-1990s according to Stogdon.
In the engine preparation area, a monorail system allows technicians to suspend each jet engine until it is rolled into a test chamber, an enormous room measuring about 90-feet long, 20-feet wide and 30-feet high. The monorail improves workflow and ensures optimum efficiency, safety and ease of use for the technicians.
Seated in the control room behind two inches of bulletproof glass, test cell operators put a variety of off-wing engines through their entire operating range to simulate the engineís flight mission. The largest being the F414-GE-400 turbofan engine with 22,000 pounds of static thrust. The F/A-18 Super Hornet and the EA-18G Growler tactical aircraft are each powered by two of these engines according to the Navy Fact Files.
Each computer-controlled test cell has a thrust capacity of 40,000 pounds and a bed capacity of 100,000 pounds. Military jet aircraft in afterburner produce exceedingly high noise levels when at maximum power settings. These aircraft are tested by spraying more fuel into the exhaust that ignites to generate additional thrust power.
A compressed air system supplies the energy required to start the jetís turbine engine. A thrust stand securely holds the engine with interface connections for fuel, air, hydraulic, oil, electrical and other systems that tie into a computer in the control room. Repeatable operations are conducted to verify results following each engine repair and reassembly.
The FRCSE test cell is designed with special air intake baffles for optimal air flow and exhaust to ensure engine performance consistency and to suppress noise to Occupational Safety and Health Administration acceptable levels. An exhaust collector and transfer tube, exhaust diffuser, exhaust plenum and exhaust stack with baffles aid in reducing heat and vibration from engine exhaust during testing.
We are not noisy,î said Curtis Kimbler, the former test engine supervisor who now serves as the TF34 engine supervisor. ìIt is one of the most people-friendly cells around. We have testing capability for the J52, TF34, F414 and the F404 engine.
The Robert Kemen Engine Test Facility was dedicated in 1978 and underwent a major upgrade in 2011.