Several weeks ago, on Friday, July 18, the Federal Aviation Administration briefed state and local elected officials about ongoing efforts to control airplane noise. The meeting was arranged by Senator Markey, who, together with Congresswoman Clark, has been very diligent in responding to the concerns raised by residents of Belmont and Watertown. The FAA, as a federal agency, is primarily responsive to federal officials.
The meeting was well attended and the presentation was useful. I spent a long time talking with the FAA managers after the meeting and more recently visited Logan for a tour of the air traffic control tower — a visit that was very educational.
Marginal improvements may be possible — and the federal authorities will continue to explore them — but I am not optimistic that we will achieve major improvements.
Here is a link to the presentation the FAA gave at the meeting and here are some of my takeaways from the presentation and the tower visit.
- Job one for the FAA is safety. Our visit to the tower brought this home in a new way for me. From the tower, one gets a new appreciation of how close those huge jets come to each other. We watched planes touching down where, only seconds before, other planes were waiting for takeoff and planes crossing runways where only seconds before other planes had been arriving or departing at well over 100mph. It’s a very small crew in the tower managing that process. Even on the relatively calm day we visited, the intensity in the room was high as the crew made quick decision after quick decision with little room for error.
- The air traffic control system has vastly improved over the last few decades. The new system (RNAV) that routes flights over Belmont and Watertown is part of a much bigger change in the way that planes are managed in the air. In the old days, planes took off and were passed from regional traffic controller to regional traffic controller without a complete calculation of how the destination airport would be able to handle their arrival. Experienced flyers may remember the days when one might spend a long time circling in a holding pattern waiting to land. Those days are essentially over as the national system manages traffic flow along defined air highways. If a given destination airport is overloaded, planes won’t even push back from the gate to go there. The traffic control system does the math to make sure that when planes take off, they’ll be able to fly straight to their destination and land without delay. The safety gains from the new system are huge as air traffic controllers have fewer planes to worry about in their airspace. The system also has huge benefits for fuel efficiency, which the airlines are very concerned about given their thin margins and the rising costs of fuel.
- Last year, the FAA completed the implementation of the new system at Logan, extending it to Runway 33L. Runway 33L (heading 330 degrees, north/northwest) is used when northwest winds dictate takeoff and landing towards the northwest. Until last year, 33L was using old “vectoring” procedures whereby planes were authorized to take off in a general direction and permitted then to branch off as expedient, leading to a wide range of flight patterns. When the new RNAV (area navigation) SID (“standard instrument departure”) path for 33L was created, it channeled the planes along safe defined pathways and those pathways happen to bring more planes over Belmont and Watertown.
- The new 33L SID was designed after very exhaustive analysis — extending over several years and involving the consideration of many alternative scenarios — with the goal of minimizing overall noise impact in the Greater Boston area. Overall, more people experience decreases in noise from the change than experience increases in noise, and none experience noise increases to the above 65 DNL level. (See page 20 of the presentation and note that the increase into the under 45 DNL category is a decrease in noise.)
- For what it is worth, overall airplane noise has been steadily decreasing in the Greater Boston Area. The total number of people living in high noise areas (above the 65 DNL level) has declined from 44,000 to 5,000 from 1990 to 2012. See my previous post for the point that 65 DNL is just much more noise than we have in Belmont or Watertown.
- The total number of flights per year at Logan has gone down by roughly 30% over the last 15 years, even as passenger volumes have risen, because airlines have changed their booking technology so that most flights run close to full.
- The more modern planes are becoming quieter and quieter as they become fuel efficient. The FAA pushes the manufacturers for improvements in noise performance and the cost of fuel has risen dramatically, giving the airlines huge incentives to modernize their fleet.
- The FAA and Massport are under a mandate to reduce noise overall and have worked very hard to reroute flights overwater and lower density areas. The technical analysis and public process have both been extensive over the past decade.
- Noise levels, have, in fact, ticked upwards recently in Belmont and Watertown as a result of the new system, but they remain well below noise levels in other areas. Our political leverage is limited given that the communities who are closer than we are to the airport do experience much greater noise. The plane noise may stand out more in generally quieter neighborhoods, but that is not, in itself, a politically viable argument for special attention.
- Despite the fact that our problems are smaller than those in other communities, MassPort, the FAA and our Congressional Delegation have been very respectful of our concerns and, through the Citizen Advisory Committee process, the FAA and MassPort are exploring runway use options to minimize uninterrupted use of any one runway — communities have argued that people shouldn’t have to wake up to the same noise they go to sleep to. Also, some have suggested that planes vary their flight paths off 33L to spread the noise a little more. I’m not sure either of these ideas is feasible or likely to be very helpful, but we will run them to ground.
So, in summary, I think the FAA has worked very hard to limit the overall noise impact from the airport and has made huge area-wide improvements in noise levels. Those improvements have not helped Belmont or Watertown, in fact, the contrary. Our congressional delegation remains very attentive to our concerns. But I don’t expect the FAA or our delegation to be able to make things dramatically better any time soon — a lot has gone into the decisions that lead us to where we are. Your state and local elected officials will nonetheless run all options to ground.
Here are some links to additional resources:
- FAA website about the NextGEN navigation system
- FAA summary of Performance Based Navigation
- FAA video about aircraft flight patterns
- Boston Logan International Airport Runway 33L RNAV SID
Final Environmental Assessment
- Boston Logan Airport Noise Study
- Listing of posts on this website about airplane noise issues.
- Study of Belmont noise monitoring site results
Addendum regarding variation of flight paths, September 5, 2014
I have continued to study and inquire about the possibility of varying flight paths to prevent those immediately under the currently recommended routes from seeing so many planes over their homes. The suggestion has been made that the planes would be less offensive if, without abandoning the basic RNAV framework, the planes could just alternate .5 miles to one side and then .5 miles to the other side. Here are some considerations which make this suggestion unlikely to be implemented:
- The whole idea of the new navigation system is to keep things consistent and repeatable. Varying routes creates more opportunities for error. Pilots have to load their planned routes in the pre-flight procedure and the fewer mistakes they have the opportunity to make the better.
- The airspace over Western Boston is very complex with takeoff and landing occurring at both Logan and Hanscom as well as considerable through traffic. Adding variations around the basic routes effectively expands the widths of those routes. The current routes have been exhaustively vetted to reliably achieve the necessary lateral separation of aircraft. Adding a mile to the width of those routes would unacceptably reduce room for error and would require readjusting neighboring routes — this readjustment might or might not be possible and would, in any event, require restarting a technical vetting process which took years to complete.
- Routes have to be fliable. The more turns you add to a route, the greater the probability that planes will fail to actually flight the routes.
- Finally, the noise data and noise physics both indicate that this modest variation in routes would make a very minor difference in noise levels on the ground — barely detectable to the ear.