Take Off Trials Confirm Noise Benefits Of `Best Practice` Flying

Confirmation that ‘best-practice’ flying procedures during take-off are producing the least possible disturbance to local communities has come from extensive trials held last summer with British Airways 747-400 aircraft leaving Heathrow.

The trials - believed to be first of their kind in the world - were carried out by British Airways and BAA Heathrow, with technical advice from Boeing and in consultation with Heathrow’s Noise and Track Keeping Working Group, comprising community and aviation industry representatives.

During the trials changes were made to take-off and climb procedures. These changes involved modifying the rate of climb, changing the height at which power is reduced and altering the point where aircraft accelerate after take-off.

The trials showed that, for 747-400 aircraft, subtle variations to current procedures could achieve noise reductions of 1 to 1.5 decibels (dBA) at 6.5 kms from ‘start of roll’, without detriment to noise performance further out. Further analysis showed that the environmental benefit of the noise reductions achieved outweighed additional fuel consumption and engine emissions.

If the new procedures are endorsed by the Noise and Track Keeping Working Group, British Airways will make them standard on all 747-400 departures from Heathrow. It will also apply them at other airports world-wide, where local conditions permit.


Hugh Somerville, British Airways Head of Environment said:

“These trials show how strong is the commitment of both British Airways and BAA to achieving the lowest possible noise levels and the best possible environment for local communities. The trials did not produce big changes in noise levels, but it would have been surprising if they had, as we have always striven for best practice.”

Other trials with older 747s were less conclusive and suggested that any improvements at 6.5 kms would be achieved at the expense of increasing noise levels further out. These trials are therefore continuing.
The successful results from the 747-400 trials open the way to further studies with other aircraft types, to see if benefits could be achieved across the British Airways fleet

The departure noise trials were part of a much wider programme of noise initiatives being taken by BAA Heathrow and British Airways to reduce aircraft noise at Heathrow and elsewhere.

These include:
* Work with airlines and ATC to achieve compliance with noise preferential departure routes

* Studies on further benefits that could be achieved from continuous descent approaches, especially at night.

* Research on ‘active noise’ at Cranfield University - a long term project which is looking at scientific ways to cancel out noise from aircraft engines

* Phasing out of British Airways’ noisiest 747s two years ahead of the regulatory deadline

* Planned investment by British Airways of £2.8 billion over the next four years on new aircraft with much improved environmental performance

Paul Fox, Safety and Security Director of BAA Heathrow commented:

“BAA Heathrow is committed to working in partnership with the Noise and Track Keeping Working Group and its local authority and business partners to seek ways of minimising the impact of Heathrow on local people. The departures noise study is just one element in a large programme of initiatives which BAA Heathrow is pursuing to reduce the effects of noise resulting from Heathrow’s operations”.