British Airways tests new Heathrow approach

British Airways is trialing new landing procedures at London Heathrow Airport as it seeks to minimize noise disturbance to residents on the glide path.

Heathrow’s proximity to London—it lies 15 miles west of the city center—and the prevailing westerly wind means that most landings are conducted over densely populated inner suburbs and there is an active anti-noise lobby.

“Heathrow is probably the most noise-sensitive airport in Europe,” BA head of environment Jonathon Counsell said. Of particular concern to both the airline and residents are a small number of long-haul flights that arrive before 6 a.m., shortly after the airport opens for the day.

Speaking at an Airbus environmental briefing in Toulouse, he said the airline will conduct four trial flights with the Airbus A380 this month using a slightly steeper approach to the runway, 3.2 degrees rather than the normal three degrees. At 10 miles out, this means the aircraft will be 300-500 feet higher.

Combined with other procedural changes, such as later lowering of the undercarriage, this is predicted to lower noise by up to five decibels, the level at which people detect a perceptible difference in noise levels.

At lower speeds, with engines throttled back for landing, airframe noise becomes a major component of what is heard on the ground; the turbulence created by the air rushing past the irregular shapes of piping around the main undercarriage legs is a significant cause of this noise.

ATW understands that aircraft and undercarriage manufacturers are looking at some form of aerodynamic shielding around the undercarriage legs to smooth the airflow on future aircraft designs.

BA will conduct further trials early next year to experiment with a two-stage approach to Heathrow, with the earlier part of the descent at four degrees, Counsell said. This would put the aircraft 1000 ft. higher at the 10-mile mark.

“It’s difficult to land a wide-bodied aircraft at that descent rate, so it will intercept the 3.2 degree glide path at 1500 feet and follow that descent rate to landing.

“The bigger and heavier the aircraft the more challenging it is, because it’s trying to speed up [at the higher descent angle]. The key is that you can program the aircraft to do it.”

BA has a company target of aiming to reduce flight noise by 15% by 2018, compared to a 2013 baseline.

(Alan Dron - ATWOnline News)