AerospaceThe development of a "silent aircraft" could bring relief to the thousands of people living close to airports, the BA festival heard. Specialists are tackling aircraft noise by taking a completely fresh look at the design of aircraft.
While commercial production of the aircraft is likely to be 20 years away, the engineers are also working on new noise efficient landing procedures to reduce noise levels in the meantime.
"The new aircraft would not be audible beyond the perimeter of the airport," said Paul Collins from the University of Cambridge.
The project is a joint collaboration between the University of Cambridge and Massachusetts Institute of Technology in the US.
The unusual shape of the aircraft is known as the "blended wing design" and is central to the reduction of noise, said Dr Anurag Agarwal, also from the University of Cambridge. "The engines are embedded above the wing at the back of the aircraft," said Dr Agarwal.
"All the noise coming forward from the engines is shielded by the wing." In effect, this creates a silent "shadow region" under the plane, he explained.
"The engines are also more acoustically efficient compared to standard engines," added Dr Agarwal.
"Instead of pushing less air at a high velocity, the jets push more air at a lower velocity." This achieves the same level of power, but creates less noise, he said.
"In addition, the new operational landing procedures that we are investigating should lead to the plane burning less fuel at lower altitudes," said Dr Tom Reynolds.
"It's a win-win situation as we can reduce noise and reduce fuel emissions at low altitude," he added.
The proposed new landing procedures could bring a reduction in airport noise as early as next year, said Dr Reynolds.
He will be testing new steeper descents in flight simulators this year and will test them at a UK regional airport next summer, he said. These procedures would eliminate the level segments of the descents currently used, Dr Reynolds explained.
The steeper descent would mean less time at low altitude with high thrust, which causes much of the noise and pollution, he said.
"Airtraffic control have had input right from the start of this work," he emphasised. "The new procedures should give us notable noise reductions."
The prospect of bringing the silent aircraft into commercial production "is a huge undertaking", said Paul Collins.
"The benefits need to be seen and accepted by industry and the market. We clearly have to win over the hearts and minds of people and show that this is technologically feasible and beneficial."