By Amy Gillentine
U.S AIR FORCE ACADEMY, Colo. -- Bird strikes cost more than $700 million in damage annually to both military and commercial airplanes -- putting both lives and property at risk.
But a group of cadets at the U.S. Air Force Academy, Colo., are working on ways to scare birds away from the aircraft, particularly during take-offs and landings; when the majority of bird strikes occur.
Led by professors in the Aeronautics Research Center, cadet research focuses on the feasibility of mounting speakers onto airplanes, using noise to frighten the birds away.
Last spring, the cadets proved that noise is an effective deterrent, but are now experimenting to find out if speakers created for helicopter use can also 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, who designed the wind tunnel experiment. "They really are designed for slower speeds, but we're seeing if they can withstand faster flight."
Helicopters generally travel about 150 mph while planes average about 260 mph. At faster speeds, volume tends to decline. The researchers are attempting to discover if the volume remains at the decibel levels necessary for birds to hear the noise and be scared away from the airplanes -- even 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."
The cadets are using one of the Academy's wind tunnels to conduct their experiments, and results on the first experiments will 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."
Cadets are investing still more effort into the idea. Cadet Blake Abrecht is in charge of research into how pilots could react to airplanes equipped with flashing lights and loud sounds to scare birds.
"We want to know if it will interfere with pilots," said Capt. Jeff Newcamp, the Academy instructor overseeing the bird-strike research. "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?"
With about 75 percent of the data collected, Abrecht says they've shown 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 begin to analyze their results during the spring semester.