At Boston Logan Airport, noise is a major problem – especially during the busiest hours of the day. Airport executives and scientists now say they have a new plan for taking on the noise issue: slowing down airplanes at takeoff. If commercial aircraft can fly slower, ground noise may solve itself.
Could slower aircraft be the key to noise abatement? The Wall Street Journal reports new data suggests slowing down by only 35 miles per hour at takeoff could make the difference between a quiet departure and a disruptive one for airport neighbors.
At airports like Boston Logan Airport (BOS) and Charlotte Douglas International Airport (CLT), changes in Federal Aviation Administration navigation routes resulted in more efficient flights, leading to less aircraft downtime and airport congestion. However, those routes have an unintended side effect: increased ground noise for the homes directly in the flight paths.
In a study funded by the Massachusetts Port Authority (MassPort) – operators of BOS – and completed by the Massachusetts Institute of Technology, computer models discovered that noise produced by airplanes were not the issue. With more aircraft being constructed from composite materials with quieter engines, aircraft noise is now being generated from their ground speed. This is especially noticeable when flights are closest to the ground during take-off and landing.
After running simulations, researches determined that reducing flight speed at takeoff from 250 knots to 220 knots at 10,000 feet could have a major effect on how airplanes are heard on the ground. Using the slower climb could quiet aircraft noise by up to five decibels, while reducing the number of houses affected by take-off. As a result, larger narrow-body aircraft, like the Boeing 757, would take an additional 30 seconds to climb to 10,000 feet.
Slower climb and descent speeds are one strategy the FAA and MassPort are considering to appease the neighbors of BOS. This summer, the administration will change navigation routes to have aircraft transfer over water, avoiding houses and reducing noise through aircraft dispersion.