Advances in aircraft noise reduction

By Luis Bravo

William N. Brownsberger (born March 21, 1957) is an American state lawmaker who serves in the Massachusetts Senate representing the Second Suffolk and Middlesex District that includes his hometown of Belmont, as well as Watertown, and parts of Allston, Brighton, Fenway-Kenmore and Back Bay, which are neighborhoods of Boston.

From 2007 to 2012 he was a member of the Massachusetts House of Representatives. He was a candidate for the Democratic nomination in the 2013 special election to succeed Ed Markey in the United States House of Representatives.

Brownsberger, very worried about the annoyances that the noises of the airplanes in the city where he lives (Belmont), took the task and wrote in his blog on the 8 of March, the following: “The Wall Street Journal describes an idea that emerges from our local efforts to reduce aircraft noise, with national recognition for the contributions of Myron Kassaraba from Belmont and a broad collaboration that includes MassPort, Adriana Poole, and the Boston West group.

Fair Skies, the Municipal Working Group for Track 33L (33L Municipal Working Group), local legislators, and, most importantly, Congresswoman Katherine Clark, this article exposes some key excerpts: Urban airports such as Boston’s Logan thought they had silenced the noise problems with quieter planes.

Now complaints come from the suburbs located 10 to 15 miles away because the new navigation routes have created a relentless noise for homeowners and residents of the area.” “It turns out that the engines are no longer the main culprits, because the new planes are much quieter. The problem is the “buz-zing” that large planes irrigate through the air. Computer models suggest that decreasing aircraft departures by 30 knots, approxi-mately 35 miles per hour, would significantly reduce ground noise. Therefore, your flight will last a few seconds longer and the airlines will consume a few more gallons of fuel.” “Hundreds of thousands of peo-ple would get some reduction and by tens of miles, it would go from being problematic to not proble-matic,” said John Hansman, pro-fessor of aeronautics and director of the International Air Transport Center at the Massachusetts Ins-titute of Technology. “Everyone saw the problem the wrong way,” said Thomas Glynn, CEO of Massport. “It’s a concentra-tion problem, it’s a frequency pro-blem, it’s not really a noise pro-blem.” Mr. Glynn says he realized how serious this problem is when My-ron Kassaraba, the representative of Belmont, MA, and a member of the Massport Community Adviso-ry Committee, showed him how Kent Johnson, a map software engineer, gathered data of the flight path. The flights before the navigation change were extended everywhere with fine green lines. The later flights were grouped in a thick red line. “The change of the before and after became apparent both vi-sually and numerically,” said Mr. Kassaraba, a financial adviser. Belmont, just over 10 miles west of Logan, had never had a noise problem. Suddenly, the noise of the airplanes distracts the conversa-tions, the work and the social activities in the garden or the patio of the neighbors. He calls the speed modification ‘a step in the right di-rection.” The reality is that the Interna-tional Center for Air Transporta-tion (ICAT) of the Massachusetts Institute of Technology – MIT has been studying aircraft noise in the communities surrounding Logan Airport, with the aim of recom-mending modifications to proce-dures to Massport and the Federal Aviation Administration (FAA) to reduce the impact of flight routes. The study included broad out-reach through community meet-ings, including with the Massport Community Advisory Committee, and meetings with FAA and airline representatives. The researchers recently published an update to their study, which included several recommendations for departures from runway 33L, and noise that affects the residents of Belmont and Watertown. First, researchers recommend reduced speed outputs. While the standard procedures vary by air-line, a typical exit includes thrust reduction at 1,000 feet above ground level (Above Ground Level – AGL) and then acceleration at an ascent speed of 250 knots. The proposal is to reduce this ascent speed to a maximum of 220 knots or a clean operating speed. This proposal has been successfully simulated for viability. However, reducing the speed of ascent would increase fuel burn and flight time. Second, the report considers the possibility of reintroducing a wider dispersion of flight routes for de-partures from runway 33L. Before the use of RNAV navigation pro-cedures, the flight paths were less concentrated and, therefore, the high noise of the aircraft was less frequent and less noticeable. There are two basic options for the rein-troduction of dispersion: the out-puts of open standard instruments (Standard Instrument Departures – SID), which are RNAV procedures that include vector radar segments for air traffic control, or flexible SIDs, which consist of instruction direct air traffic control, for e-xample, in the altitude of an airplane. Some of the next steps for re-searchers include determining a minimum speed of clean operatio-nal ascent for common aircraft types, and developing a method for comparing open and flexible SID options in order to assess the impact of noise redistribution. Then, ICAT will evaluate the obs-tacles to the implementation of its recommendations, including the performance of the aircraft, navi-gation and flight management, the flight crew and the workload of air traffic control and security. Based on their results, they will recom-mend modifications to Massport and the FAA. We ask ourselves, if all this research work is done to avoid the annoying hum of planes in Bel-mont, will they also implement it in East Boston, where not only noise is the main problem gene-rated by Logan airport and where more than 50% of the population is Latino?