Also, planes generally take off at the same height, regardless of runway length. That height is, of course, ground level. That’s where all flights start, you see.

There is much more to noise than isolated engines.

However, runway length does not play a role in community aircraft noise. None whatsoever.

An aircraft has a set rotation speed (when it lifts off the runway), its fixed, either your runway is long enough to safely attain it, or it is not. You could make the argument that the aircraft would be at a higher throttle setting while on the runway to accelerate to this rotation speed, but that does not impact community noise in any significant way (in fact, the difference would be barely measurable at the airport boundary fence).

Post rotation off the runway, the aircraft can (and for city airport, will) employ throttle cut-back procedures to reduce noise; but that is completely independent of runway length.

You folks need to focus your energies in the right direction. For instance, instead of focussing on passenger transits, which is actually quite detached from the problem, you should be focussing on aircraft transits, the maximum allowable noise of each of those transits and the time of day of each of those transits.

So, if you allowed the bigger runway, and simultaneously limited the number of flights, determined the aircraft that are allowed to use the airport on a noise basis and fixed the allowable noise at different times of day, everyone would win. The airport could put through more passengers, there would be less flights, and each flight would be quieter.

I do appreciate aircraft noise is a problem, its a massive problem – but you guys really need to help yourselves by aiming in the right direction!

Also there’s more to noise than engine ratings. Runway length – or lack thereof in the case of he City airport – plays a big role in how hard those engines have to work, and thus how noisy they are. It’s too easy to hide behind manufacturer specs which fail to tell the real story of how aircraft noise affects people’s lives.

Taking the Ryanair 737-800 (~160 seats) as a reference point for comparison, it is rated at R4 relative to the ICAO Chapter 3 noise standard (that is, 10 EPNdB below the standard).

Now compare that to a number of other aircraft:
A321 (~200 seats) – R4 rated
A330 (~290 seats) – R4 rated for Pratt & Whitney engines, R5 (that is 15 or more EPNdB below the ICAO Chpt 3 standard) for all Rolls Royce engines
Boeing 777 (~425 seats) – R4 for all Rolls-Royce engines, R5 for Pratt & Whitney and General Electric.

So, in summary, if you allowed more passenger transits, you’d probably have larger, quieter planes flying less flights.

I expect this post to be deleted as all too often these well meaning campaigns end up being run on perception, rather than on reality. Reality is then denied as it would undermine the whole campaign.

Congratulations on giving us ‘little people’ a little hope that we can stand up for our quality of life – and win!

It’s easy to make stats up, and it’s even easier to comment without doing any research. Belfast City Airport Watch estimates that over 40,000 Belfast and Holywood residents are affected by aircraft noise. That estimate is the result of a public survey and similar extrapolation techniques as used in election polls.