British Airways testing modified landing procedure at Heathrow to reduce aircraft noise

The subject of noise pollution has long been a problem for Heathrow Airport bearing in mind its location 15 miles to the west of the center of London, while normal westerly prevailing winds which further accentuates the problem. For some time there has been a very active and growing anti-noise lobby who are also anti-expansion, which has created problems for the plans to extend Heathrow’s capacity by building a third runway. In addition, the airport is restricted to the volume of night-time traffic where there are no take-offs after 11.30pm and only 5,800 planes may land between 11.30 pm and 6am in any calendar year. Of the approximate 20 flights a night which land, around 16 land between 4.30 am and 6am. According to BA’s head of environment, Jonathon Counsell, “Heathrow is probably the most noise-sensitive airport in Europe.”
At an Airbus environmental briefing in Toulouse, Counsell made it clear that this month British Airways will conduct four trial flights with the Airbus A380 which will adopt a slightly steeper approach flightpath to the runway of 3.2o as opposed to the standard 3o. At a distance of ten miles from the airport this results in the aircraft flying at an altitude which is increased by between 300-500ft. Along with other small changes, including a delayed lowering of the undercarriage, it is anticipated this will help to reduce noise levels by some 5 decibels, which is an audibly noticeable difference. When flying at lower speeds and with engines throttled back ready for landing, airframe noise is a massively contributing factor to the overall noise of a plane, much of which is caused by wind passing over irregular shapes within the structure of the landing gear. As a consequence, it is believed undercarriage manufacturers are looking into creating a form of cowl to smooth the airflow around the landing gear.
It is also believed that further trials will take place to increase the angle of descent to 4o, which would further increase the altitude by another 1,000ft at a distance of 10 miles. However at an altitude of 1,500ft the trajectory would reduce back to the new 3.2o as the biggest problem with increasing the angle of descent is the plane’s natural tendency to want to speed up. This trial is part of British Airways’ commitment to reducing noise levels of aircraft by 15% compared to 2013 levels by 2018.