Can We Quiet the Sky?

Aircraft: good. Aircraft noise: bad. This dichotomy has split many populations right down the middle for half a century and is only intensifying as demands for access to the skies and to urban accommodation grow. Battle lines are drawn, with entrepreneurs, environmentalists, politicians, travellers and town planners entrenched and hostile and no one happy but lawyers.

Is there an answer? With sagas of dispute stretching over decades for many of the world's largest airports (and not a few that are more modest), maybe looking at history can help. It can certainly teach some lessons:

For a start: political promises have a sell-by date. The list of absolute guarantees of "no further expansion," "not another runway," "never more a night flight" is long, but the list of "someone else signed up to that one" is not much shorter. In a world of political priorities that can change overnight, a term of office is a very long time, and a decade is the unimaginable; white on the map.

For another: in the world of quiet, technology is king. Surprising as it may sound, today's planes are orders of magnitude quieter than many of their predecessors, and less than 0.02 percent of the energy they produce is now in the form of sound.

And one more: in complaining, what counts is quantity. The larger the number of people that write in, speak out, vote for someone else, the more likely change becomes. This is unfortunate since air noise pollution, and the numbers affected by it, usually increase gradually. In this field there are rarely events which galvanise large numbers of people into action. Rather, the volume of complaints remains fairly constant while the numbers that suffer and the amount they have to endure slowly build. The consequences are ill health, reduced work performance, impaired learning in children and wider and deeper unhappiness. The lack of power of the individual to combat the noisemakers adds very significantly to the distress.

Can a way forward be found from these points? Perhaps so. Technology is the first part of the answer: although jet engines themselves are now probably as quiet as can be, the idea of wholesale plane redesign with the primary purpose of reducing noise is largely untouched, save for one relatively little-known but quite successful project a decade ago: the silent aircraft. In this radical rethink, a cluster of new ideas were explored, including mounting the engines above the wings and using the whole plane as a flying surface. The project was not intended to build an actual vehicle, but simply to explore its possibilities. But its conclusions offered great promise.

And the idea of fundamental technological rethink can go further: why not use different transportation results for different payloads. We don't transport bricks by bus or milk by moped, so why transport non-urgent goods by plane? There are high-tech airships that could do the job and almost in silence: and cheaper and greener too. With no need for sophisticated airports for take-off or landing, such craft need not compete with aircraft for landing spaces either.

To be adopted, technologies like these need capital, and that means political will -- which in term requires healthy doses of support from potential voters. Quiet solutions will always have the support of the noise-weary, but exciting new aircraft will win plenty more advocates on their own terms. Concorde was much loved by many despite being perhaps the worst ever plane in terms of noise impact. Imagine what another bright new delta-wing might do -- a quiet one this time. And balloons have their own stately magic too.

There are many more examples of quiet solutions like these, examples that go beyond the usual suspects. It's time to change the debate.