| BAA QUESTIONS & ANSWERS ON ARRIVALS MAPS
The text below under the heading QUESTIONS & ANSWERS: ARRIVALS MAPS has been produced by BAA; we have reproduced it as originally written with a few minor adjustments to reflect that it is appearing on the SSE website. We add three comments to bear in mind when examining the maps:
1. The figure of 65% for arrivals from the north east is an approximate long term average over the years. This figure can vary quite markedly from year to year, let alone over shorter periods.
2. SSE cautions readers to examine BOTH maps carefully when considering the noise effects of arrivals at any one location. In addition it is important to consider any possible effects from departures (see Noise Preferential Routes Map)
3. The statistics in the boxes apply only to the points where the boxes
actually are (see the arrow nearest the box in each case); this is
because farther out there can be sub-divisions in the swathe reflecting the
fact that aircraft are arriving from several different directions. When
considering the statistics in the boxes, care is again required to ensure
that movements reflected on BOTH maps are taken into account.
QUESTIONS & ANSWERS: ARRIVALS MAPS
What are arrivals maps?
These maps show the typical patterns of where planes fly on their arrival to Stansted
Airport. Both maps use actual aircraft tracks for an average week in summer 2005.
Who has produced this information?
The Environmental Research Consultancy Department (ERCD) of the Civil Aviation
Authority (CAA) was commissioned to produce this piece of work for Stansted.
Why have the maps been produced?
BAA Stansted wanted to provide easy to understand maps, showing where planes
arriving into Stansted Airport usually flyin order to help peopleunderstand the patterns of day to day operations.
Who have they been produced for?
Members of our local community and they form part of specific information available
for people moving within the local area or who wish to find out more about operations
at Stansted. They are available through BAA's Flight Evaluation Unit (FEU) on 0800
743 288 and are also on BAA's website www.stanstedairport.com/noise.
Are the routes new and is this new information?
These maps show current routes and information previously available in various
different ways. They are a new initiative designed to show the typical patterns and
heights of aircraft arriving into Stansted Airport.
Why are the tracks coloured differently?
Each aircraft track is shown in three different colours along its route. The yellow
band shows aircraft at between 6,000 ft and 10,000 ft. The light green band shows
aircraft at between 6,000 ft and 3,000 ft. The dark green band shows aircraft at below
3,000 ft. Generally, the higher the aircraft are the quieter they will be.
Why are there two maps?
There are two maps which represent arrivals to both ends of the runway, because the
approach changes depending on whether the wind is in a westerly or easterly
What is the information in the small boxes?
This information gives details of the range of how many flights you could expect to
see during a 24 hour period; the average percentage of flights a day; the average number of days with less than 10 flights and the average number of days with more
than 10 flights.
What are the arrows showing?
The arrows are an indication of the direction the aircraft are moving in.
Why are there two runway directions?
Stansted has one runway and the direction of the wind determines which end is used
for taking off and landing planes. Stansted's predominant wind direction is from the
south west, so aircraft land from the north east and take off towards the south west.
This happens around 65% of the time.
What directions are the aircraft coming from on both maps?
For arrivals landing towards the south west, aircraft are coming in from both the east
and west to line up with Stansted's runway.
For arrivals landing towards the north east, aircraft come from a number of directions;
to start their approach they come from the south, east and west.
Why are the average daily figures based on 92 days rather than the picture
showing a week of tracks?
The 92-day summer reporting period from mid-June to mid-September has been in
use for many years now as the established time scale over which to describe the noise
exposure arising from aircraft.
What does average daily arrivals mean?
This is the average number of arrival movements at each location over the 92-day
summer period. The figure allows the user to gauge how many arrivals they can
expect on an average summer day. It is calculated by taking the sum of all the arriving
aircraft within the summer period at each distinct location and dividing that number
by the number of days, in this case 92. Because the average number of daily arrivals
is affected by the runway direction that is in use, this statistic is complemented with
the statistic 'daily range of arrivals', which is described below.
What does daily range of arrivals mean?
The statistic called 'daily range of arrivals' provides an indication of the minimum
and maximum number of flights recorded over the summer period at each location.
Why are there no set routes for arriving aircraft?
There are no set routes for arriving aircraft as there are for departures, as air traffic
control (who direct the planes) need the flexibility to safely separate and sequence
aircraft within the airspace when on their final approach to Stansted.