On a quiet open space within the Eglin Air Force Base, Fla., range, an F-15EX Eagle II crested a small hill at 500 feet with afterburners blazing.
The Air Force’s newest fighter crossed over vertical and horizontal rows of microphones on the ground that captured every decibel of sound the aircraft made as it roared by and began to turn for another pass.
That’s just one of the many sound recordings that took place during the F-15 acoustic testing that occurred here over the last two weeks.
This was the first such testing on the F-15 since the aircraft’s initial roll out in the early 1970s and the first ever on its GE-129 engines. The Department of Defense-initiated test was done exclusively on the F-15EX as it will be the new model in Air Force inventory.
The goal of the acoustic testing is to establish a baseline of sound data, so DOD can update predictions and models of the noise levels in locations where the new aircraft will fly and be stationed, according to James Potter, Department of the Air Force community planner.
The tests consisted of ground testing at idle and with engines running as well as flight testing at various heights and aircraft configurations. Blue Ridge Research and Consulting, the contractor capturing the sound data, used more than 100 microphones strategically placed around the aircraft for the ground testing. Around 35 microphones were spread 4,000 feet laterally and 1000 feet horizontally to capture the sounds of the more than 70 Eagle II flyovers.
Eglin’s Operational Flight Program Combined Test Force, F-15 Section, was responsible for coordinating all the requirements to make the test happen as well as the management of all the moving pieces during the process.
“As the lead developmental test organization, the OFP CTF enabled DOD to meet their deadlines for the environmental impact study and we are now one step closer to getting this new aircraft into the hands of the warfighter,” said 1st Lt. Zachary Arns, OFP CTF deputy mission support section chief.