any chance of quiet aircraft ever seeing the light of day

[diddy1234]

I am not too sure which section to post this in, so if this is the wrong section please advise.

As part of the company that I work for we had a very interesting chat about the study into quiet aircraft.

Details here :-

Team moves toward silent, eco-friendly plane - MIT News Office

As part of the study into reducing aircraft noise, MIT and Cambridge University (paid for by the government) proposed a new design that was also energy efficient.
From my understanding Boeing were also performing studies into this as well.

Typical take off noise figures were lowered to 63db (loud talking noise levels).

That's quite an achievement.

There were some downsides to this aircraft :-
Servicing and access to the engines.
30% cost increase in manufacture compared to conventional aircraft.
Small technical issue with Turbofan and bypass fan technology but this is mostly resolved with Pratt & Whitney
geared fan technology.

So apart from the minor issues above, why is no one going to build it ?

With ever increasing complains from noise nimby's and more aircraft movements, I would have thought that this would have progressed further than just a two year study........

Also if these aircraft existed, would you travel on one ?

RD

[SNS3Guppy]

Aircraft are being parked across the board right now. Furloughs, layoffs, fleet reductions. Aside from the actual cost of the aircraft being 30% higher, when fewer new aircraft are being purchased...to whom are these new quieter airplanes to be sold?

Most of the world doesn't care about quiet, and a lot of the globe operates on a budget.

Stage IV noise restrictions are coming...how much more quiet to you want it?

[Pugilistic Animus]

you can barely hear the jets today

and that's no way to impress kids

[Karl Bamforth]

If aircraft were silent and invisible someone would still complain.

Slightly different tack, the US, were operating a very quiet aircraft as a sort of cheap spy plane in,I think Vietnam (might be wrong) it was a heavily modified motor glider type thing and virtually silent above 100ft.

The technology was available to reduce noise in GA aircraft some time ago but has not been totally taken up.
Expense would be one reason, I am sure there are many others.

[chevvron]

There is a super quiet motor glider cum microlight in existence which was produced by Angus Fleming at Membury; can't recall the name of it but it had the suffix 2-32 to indicate a 32hp engine which was a Konig 4 cyl radial 2 stroke. Angus did try the Midwest Rotary single rotor and a Hirth flat four both of 45 hp; the Midwest had too high an egt apparently (over 1000 deg C!) but the Hirth was almost as quiet as the Konig, and it was in fact the first Chevvron (damn - given the game away) I flew.

[Reimers]

From my understanding Boeing were also performing studies into this as well.

So apart from the minor issues above, why is no one going to build it ?

You make it sound as if the studies have been completed a long time ago and that now this mature technology is sitting in some desk unnoticed.

But the linked page clearly states

The project aims to develop aircraft by 2030.

So you see how fast things move in the aviation industry. As this paper is from 2006, some more development propably has taken place, but given the timeframe concerned, I'd not expect any of the aircraft currently being developed (e.g. 737 Replacement, A320 Replacement) to be anything like this.

[aviate1138]

Chevvron.

The namesake was great for nap of the earth flying but things happened very slowly, other than the time D Piggott had the entire top fabric surface of one wing unglue itself. Needless to say DP spiralled gently into a field and walked away. Or is that just an urban myth?

Preferred the CFM Shadow

[AnthonyGA]

I guess I must have a long memory. I remember when jets were truly loud. Today, noise from the highway and city streets easily drowns out the sounds of aircraft—I wonder why nobody seems to complain about that. I used to live under a major approach path for an equally major airport, and I hardly ever noticed the jet aircraft flying over the house at 5000 feet AGL or so. Same with GA props (which were never that noisy anyway). Aircraft just don't make that much noise unless your house is nestled beneath the approach lights.