The International Center for Air Transportation (ICAT) at MIT has been studying noise from overhead airplanes in the communities surrounding Logan Airport, with a goal of recommending procedural modifications to Massport and the Federal Aviation Administration (FAA) to reduce the impact of the flight paths. The study has included extensive outreach via community meetings, including with the Massport Community Advisory Committee, and meetings with FAA and airline representatives. The researchers recently released an update on their study, which included several recommendations for departures coming off of runway 33L, noise from which affects Belmont and Watertown residents.
First, the researchers recommend reduced speed departures. While standard procedures vary by airline, a typical departure includes thrust reduction at 1,000 feet above ground level (AGL) and then acceleration to 250 knots climb speed. The proposal is to reduce this climb speed to the greater of either 220 knots or a clean operating speed. This proposal has been successfully simulated for flyability. However, reducing the climb speed would increase fuel burn and flight time.
Second, the report considers the possibility of re-introducing broader dispersion of flight paths for departures from runway 33L. Before the use of RNAV navigation procedures, flight paths were less concentrated and therefore noise from overhead airplanes was less frequent and less noticeable. There are two basic options for re-introduction of dispersion: open standard instrument departures (SIDs), which are RNAV procedures that include radar vector segments from air traffic control, or by flexible SIDs, which consists of direct air traffic control instruction based, for example, on an aircraft’s altitude.
Some next steps for the researchers include determining a minimum clean operating climb speed for common aircraft types, and developing a method of comparing open and flexible SID options in order to evaluate the impact of noise redistribution. ICAT will then evaluate implementation barriers to their recommendations, including aircraft performance, navigation and flight management, flight crew and air traffic control workload, and safety. Based on their results, they will then recommend modifications to Massport and the FAA.
Senator Brownsberger’s Office