Independent Aviation Noise Authority (Supplementary) [4]

Session date: 
June 18, 2014
Question By: 
Tony Arbour
GLA Conservatives
Asked Of: 
Sir Howard Davies, Former Chair of the Airports Commission


Tony Arbour AM:  Arising from the last point that Mr Tracey raised, you told us that on the basis of what you already knew it is likely to be true that a third runway is going to generate less noise than two runways.  I may say that my constituents in Hounslow and Richmond have frequently heard assertions saying, “More means less”, which has not proved to be so.


I wonder if you can tell us on what you base your certainty that there will be a smaller noise footprint from a third runway than there is from the existing two runways.


Answer for Independent Aviation Noise Authority (Supplementary) [4]

Answer for Independent Aviation Noise Authority (Supplementary) [4]

Answered By: 
Sir Howard Davies, Former Chair of the Airports Commission

Sir Howard Davies (Chair - Airports Commission):  Sorry, I have not said that.


Tony Arbour AM:  I thought that you had said just to my colleague Assembly Member Tracey that ‑‑


Sir Howard Davies (Chair - Airports Commission):  No, I did not.  I said that what Heathrow has put forward is its forecast of what the noise impact of a three-runway airport would be.  In its submission - and I said this in response over here - it says that the overall impact would be less with a three-runway airport in 2030 than a two-runway airport today because of the change in the fleet mix.  That is a forecast and an assertion that we are currently testing.  We have consultants looking at that to see how reasonable it is.  I have certainly not said that I am certain about that.


Tony Arbour AM:  I am extremely relieved to hear that, Sir Howard, because my constituents have frequently received assurances from Heathrow going back many years, “We will not want an extra terminal”, yet they do, and, “We will not want an extra runway”, and of course they have said that this time.  They always come back for more.


In relation to noise and the alleged reduction in the noise footprint, would you accept that you can be woken up by a quiet plane as much as a noisy plane?


Sir Howard Davies (Chair - Airports Commission):  You can be woken up by the neighbour’s dog as well.  What one needs to do is to look at the decibel levels.  We spent the early morning yesterday in Hounslow with the council.  We had a noise monitor and we were looking at the decibel levels of different aircraft and at what the noise mitigation could be for those aircraft to reduce that noise down to ambient noise level.  That is the territory one needs to be in and that is quite promising.  The impact of the different fleet mix is actually quite noticeable.  If you sit underneath a 747 versus an A340, you can tell the difference.  The impact of insulation can be quite significant and can reduce that down to an ambient noise level.  That is the way one should go.


I am not sure it is useful for me to say yes or no to the question of whether or not you could be woken by a quiet plane.  It depends on how deeply you sleep.  I sleep rather deeply because I have a clear conscience, Assembly Member Arbour.


Tony Arbour AM:  Obviously.  Effectively, the point I am making is that we know that different people will be affected by noise should there be a third runway.  It is perfectly true that you can be inured to noise and you get used to it, but certainly at the very beginning my other constituents who live in Chiswick really see this with foreboding.  They say it does not really matter how quiet the plane is.  Unless it is completely silent, they will be woken up by the plane.


Again relating to assertions made by Heathrow in relation to the number of aeroplane movements and the amount of noise that those aeroplanes will make, so far as you can tell - and I accept that you are looking at their submissions, which comes back my first point - are their submissions actually based on fact or are they based on hope?


Sir Howard Davies (Chair - Airports Commission):  In terms of the number of movements, what we would be quite certain about, or what I hope we could be fairly certain about, is the maximum number of movements that would be possible with a third runway.  Of course, that is not the same as the number of movements that should be allowed under a third runway because at the moment we have a planning cap for Heathrow of 480,000 air traffic movements a year.  If that cap were lifted, the airport could do a few more than that.  Not that many more, but it could do some more than that.


The issue is, firstly, what a third runway would allow you to do and, secondly, what the authorities should allow that third runway to do.  That might be a different answer because you might say they can have a third runway but only if the maximum number of flights is X, perhaps related to certain hours and limitations, etc.  You then have to iterate back and say, if you did impose that restriction, would it be a viable project or is it too restrictive?  Obviously, if you said to them, “Yes, you can have a third runway but you can only have 5,000 more flights”, they would not build it.  Then the question is what an economic balance would be versus the noise nuisance.  All of those things are capable of being modelled.


What we are doing at the moment is modelling the airspace implications of that because you have to look at what the implications of an expansion of Heathrow would be for Northolt, Luton and elsewhere in order to get a reliable picture of what the implications of a third runway would actually be.  That is where we have consultants working for us on environmental issues, noise issues, airspace issues, etc, and we will be producing the results of that in the autumn for consultation.