The sonic nets have been shown to reduce the number of birds in an area by up to 80 per cent

Sonic nets installed in airfields shown to prevent bird collisions

Sonic nets could be installed around airfields in order to prevent collisions between birds and aircraft.

The device emits sounds equivalent to the levels heard in a busy restaurant to discourage birds from entering the area.

The researchers behind the proposal believe such a system could save passengers' lives, as well as billions of pounds in damages.

Professor John Swaddle found that filling a controlled area around an airfield where the majority of collisions occur with acoustic noise can reduce the number of birds in the area by 80 per cent.

Bird strikes supposedly cost the worldwide aviation industry billions of pounds annually and were linked to 255 deaths between 1988 and 2013.

Techniques to deter birds from airports include shooting, poisoning, live-capture and relocation, and the use of scare technologies, but these have proved largely ineffective.

Swaddle believes his solution is a benign and relatively cost-effective solution to the problem which would see the 24-hour broadcast of noise in the area to interrupt bird communication.

The researchers set up speakers and amplifiers in three areas of an airfield in Virginia, USA, and observed bird abundance over eight weeks - the first four weeks without noise and the second four weeks with the noise turned on.

Results showed a large decrease in the number of birds in the sonic net and areas just outside. The technique was particularly effective at deterring a number of species that are at high risk of bird strike such as starlings.

"We have conducted prior research in an aviary but this is the first study done out in the field to show the efficacy of the sonic net," Swaddle said.

"We are using a different kind of deterrent - trying to stop birds from hearing one another by playing a noise that is at the same pitch as the alarm calls or predator noises they are listening out for.

"By playing a noise at the same pitch, we mask those sounds, making the area much riskier for the birds to occupy.

"The birds don't like it and leave the area around the airfields, where there is potential for tremendous damage and loss of life."

There was also no sign of the birds becoming used to the noise which was set at a level louder than a domestic dishwasher but no more than that of a noisy restaurant.

"These findings have implications for airport safety but also have potential applications for agriculture and for alternative energy sources such as solar farms, where birds living and feeding in the area can cause disruption, and around wind turbines where the birds are at risk of collision and the threat to birds can sometimes be a legislative barrier," Swaddle added.

Meanwhile European aviation safety authorities have set up a task force to urgently assess the dangers of collisions between drones and aircraft after a rise in near misses with passenger planes.

The use of civil drones, whether for commercial purposes such as crop surveillance, monitoring of natural disasters, photography or leisure, is rising and aircraft pilots are increasingly reporting near-misses.

Last month, a British Airways passenger plane was suspected of having hit a drone as it approached Heathrow airport although it was later thought that it may have just been a plastic bag.

The European Aviation Safety Agency, which will lead the inquiry, said it will examine how vulnerable aircraft windshields, engines and airframes are to impact with drones.

Intel has developed a technology called RealSense that allows drones to sense and avoid obstacles, which started being incorporated in consumer products at the beginning of this year.

Sign up to the E&T News e-mail to get great stories like this delivered to your inbox every day.

Recent articles