The aim of increased air traffic is at the heart of the proposal to increase the length of London Southend Airport’s runway however, little if any, published information is available about the height that all aircraft will operate.

Whilst hoping that air-traffic control would operate a despatch system that would distribute aircraft over a range of directions once they had reached a safe altitude at which to turn, little can be done to move the traffic laterally either side of the approach glide path.

Glide paths appear to be set internationally at 3 degrees from the horizontal to place the landing aircraft at a position approximately 1,000ft on to the runway and 50ft in altitude for “flare-out” where the pilot commits to the plane landing.

Therefore, if one plots a graph of vertical height against ground distance from an angle of 3 degrees, one can easily produce a guide to the expected heights of all approaching aircraft at any given distance from the runway.

Using this method indicates a current aircraft altitude at Leighview Drive of 510ft. However, the land height difference between the airport and Leighview is indicated on the Ordnance Survey as 25 metres (81.25ft).

So the current expected height of the glide path is nominally 420ft from which must also be subtracted the height of houses and Blenheim School giving an approximate clearance of 370ft.

There is an allowed variation at this distance from flare-out of a further 16.5ft up or down, bringing the clearance to 353.5ft.

If the runway is extended, the flare-out point is brought closer to Leighview and the heights are reduced to 388ft ground clearance; 338ft building clearance with an allowed variation bringing it down to 322ft.

The reason for centring this example on Leighview Drive is that this is probably the highest land point on the approach to the airport.

Thanks to Peter Finlay for this information

Note: Shortly after publishing this item, we received an email from a retired aviation executive, who tells us that the above figures don’t take into account that apparently it is intended that an approach angle of 3.5° will be used and a new “ILS” system that would be installed if the runway were extended. This, he claims, would mean that aircraft would be 23ft higher over Leigh View Drive than is claimed above – at a height of 411ft.

What he fails to identify is that 23ft isn’t really very much when you have a large plane going over your house every five minutes.

Response from Anne-Marie Griffin, Chair of Fight the Flights

It is very interesting to read Mr Stockwell’s email. However there are two very important issues which he fails to mention in relation to the level of flights descending or approaching: noise and air pollution. It is the human impact and effect on the communities which appears to be constantly overlooked : the experience of aircraft noise is a disruptive and stressful experience and there are plenty of studies which show that being regularly exposed to high levels of aircraft noise have a direct link to cardiovascular diseases in humans and affect the development of children.

I do not believe that an an extra 23ft in height would make any difference whatsoever in the level of noise that residents would experience. Essentially it is the noise which initially worries people when faced with expanding flights and the prospect of larger planes, and of course safety, particularly if any homes are to find themselves in the crash zone (public safety zone).

You’d have to have a lot of confidence in the ability of ‘noise mitigation’ to stop or minimise jet noise from affecting residents inside their homes based on Mr Stockwells calculated level of flights at 411ft above the drive in question. Noise mitigation appears to be a complete dissapointment to most residents who have received it at other airports, if indeed their property falls into the criteria (which is no mean feat in itself even if you are in the noise contour zone). It is possible that noise mitigation may take around 3dbs off the noise inside the home (from what I understand) which is not at all adequate in itself. But it is worth considering what your experience will be of the noise if you wish to spend time outside in your garden, or indeed might like to open your windows, or see your children develop their reading and memory skills in the same way as children who do not live or go to school beneath increasingly busy flight paths. Not everyone has a choice in where they live.