UK seeks Silent Aircraft
 

By Lester Haines
Published Thursday 27th May 2004 15:22? GMT

Today saw the launch of an ambitious ?2.5m, three-year project led by Cambridge-MIT Institute (CMI) - the Silent Aircraft Initiative (SAI). Its plan is pretty simple: to produce aircraft "whose noise emissions would barely be heard above the background noise level in a typical built-up area".

The initiative boasts an impressive manifest of partners, including British Airways, the Civil Aviation Authority and Roll-Royce. It also aims to consult representatives of community groups opposed to aircraft noise - a sensible move given the current brouhaha over the proposed extension to London's Stanstead Airport and ongoing protests surrounding increased air traffic at Heathrow.


According to Cambridge SAI professor Ann Dowling - quoted on the SAI website - "The civil aviation industry is already introducing small, incremental decreases in aircraft noise. But we are aiming for a radical change in noise levels - so that beyond the perimeter of the airport, the noise of aircraft flying would be imperceptible to the public."

All well and good, but how? We asked project manager Paul Collins if the research would centre on existing jet turbine technology, or would it embrace newer, more radical solutions? He confirmed its radical nature, but noted that "it still flies and carries passengers and yes, it's still powered by gas turbines".

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useless invention

miltary applications, cruise missiles.

Anything subsonic .. imagine a silent a10 ? = bad day.

prop aircraft produce most noise from the propeller, not the engine.

and progress can be made by slowing down prop rpm and increasing the pitch of the blades.

there are some observer aircraft that do this now (european) and from 500 feet agl you cannot hear them.