Searching for the sound: Academy cadet researchers work to end bird strikes

  • Published
  • By Amy Gillentine
  • Office of Reseach
U.S AIR FORCE ACADEMY, Colo. --  A group of Academy cadets has flocked together and come up with a noisy proposition: using loud sound to decrease the changes of a bird strike on a plane during takeoff and landing.
A bird strike or "BASH" - Bird Aircraft Strike Hazard -- is a collision between an airborne animal and an aircraft, and the majority of these strikes occur during a plane's takeoff and landing, causing more than $700 million of damage to military and commercial planes and putting lives and property at risk.

Led by Aeronautics Research Center professors here, cadet research focuses on the possibility of mounting speakers onto airplanes, using noise to frighten birds away.
Last spring, the cadets proved that noise is an effective deterrent, but they're now investigating if speakers designed for helicopter use can be used on faster aircraft without damaging the speakers or losing volume.

"We are seeing if we can incorporate the type of speakers that are already designed for flight," said Cadet 1st Class Nathan Armes. "They really are designed for slower speeds, but we're seeing if they can withstand faster flight."

According to Capt. Jeff Newcamp, the Academy instructor overseeing the bird strike research, helicopters generally travel about 150 mph while planes average about 260 mph. Volume tends to decline at high speed so the cadets are exploring ways to keep the volume at decibel levels necessary to scare the birds from airplanes traveling at faster speeds,
"The average bird has a hearing between 1,000 hertz and 4,000 hertz," Armes said. "So far, we know the speaker can be heard at 2,000 hertz. We're pushing the speaker beyond its production limits. What we found is that we're losing decibels at faster speeds, but there are some points when it can still be heard."

Cadet researchers are using an Academy wind tunnel to conduct their experiments; the results of the first experiments should be available by the end of January.

"It's definitely within the realm of feasibility," Armes said. "We're still assessing if it's effective at higher levels and at stronger wind speeds."  Armes designed the wind tunnel experiment.

Cadets are also researching how pilots could react to airplanes equipped with loud noise and flashing lights.

"We want to know if it will interfere with pilots," Newcamp said. "So, we're including that in the flight simulator. If there's an aircraft landing, and there's another plane with flashing light and noise - how will another pilot respond?"

Cadet 1st Class Blake Abrecht is in charge of this portion of the research. With about 75 percent of the data collected, he said the research shows that pilots perform slightly better with the flashing lights and noise.

"Maybe it just helps them concentrate more," he said.

Cadets will finish gathering data this semester and analyze the results in the spring semester.