Why so noisy this summer?

There are a number of factors contributing to the increase in noise this summer. One of the most significant reasons has been prevailing winds out of the north and northwest. In a typical summer, the wind is more often from the south and southeast, which allows (and sometimes requires) the airport to operate in a “south flow” (meaning that departures go off the other end of the runway over Eagan and Mendota Heights). However, this summer’s wind conditions were unusual and therefore, a “north flow” was used more frequently, with departures going over Minneapolis. While the wind sometimes dictates the flow of the airport, there are conditions where either flow could be selected – more on that later.

Also, in the summer, the thinner (less dense) air from warm temperatures affects the altitudes of airplanes: they fly lower. A recent analysis showed that in our community, the average altitudes of airplanes can drop 700-800 feet when comparing July to January. That’s significant. This summer (because it was not very hot) the planes were flying lower on average but not quite as low as they would normally be in a typical summer.

In general, the summer is the busiest time for MSP, with the most operations occurring in July and August. This July was exceptionally busy with 6,888 departures off of 30L compared to 5,862 last year (departures from runway 30L are the departures which tend to impact our community most directly, particularly the Kenny and Armatage neighborhoods). In June, there was some additional traffic related to the MLB All Star Game and an increase in nighttime flights over Minneapolis.

The final major factor in this difficult combination is runway use. In July, MSP used runway 30L for 36.8% of all of the departures from the airport. Last July, this runway was used for 29.5% of all departures, which we already thought was too much. We want to see a more balanced use of all the runways.

While some of these factors were unique this summer, there are a few concerning factors that are part of a longer-term pattern that I'd like to address. We are concerned about how often the airport operates in a “north flow” with departures over Minneapolis, and how often runways 30L and 30R are used. We are also concerned that a single runway (12R) is being used for a disproportionate number of nighttime arrivals.

Can we get some relief?

Since 1972, a preferred runway system has been in place at the airport. The current iteration is known as the “Runway Use System” (RUS). The RUS is a list of runways in the order that they are preferred to be used.  The FAA and Metropolitan Airports Commission (MAC) have been partners in developing the RUS and the purpose of it is to send planes over less populated areas whenever possible.

The current list of preferred runways (as of 2005) is as follows:

Departure Preference

1.    Runways 12L/R
2.    Runway 17
3.    Either Runway 22 or 04
4.    Runways 30L/R

Arrival Preference

1.    Runways 30L/R
2.    Runway 35
3.    Either Runway 22 or 04
4.    Runways 12L/R

If you are not very familiar with the runway numbers, the gist is that whenever possible, airplanes should depart and arrive over Eagan and Mendota Heights.  When that cannot be done, they are supposed to use the other runway options before going over Minneapolis.  There are admittedly limitations to this system. When departures are going over Eagan and Mendota Heights, that generally means that arrivals will go over Minneapolis. However, sometimes when the number of operations is low (usually only possible at night) the airport can have “head-to-head” operations—arrivals and departures using the same end of the runway. 

In May, MAC produced a study for the Noise Oversight Committee (a group created to advise the MAC on noise-related issues) about how well the RUS was being used. The report showed what we already suspected: the RUS is not being used effectively.  The report essentially says that when the airport is busy, the FAA prefers to use the “north flow” configuration which sends departures over Minneapolis. The report then concludes that the airport is busy from 7 a.m. to 10 p.m.  It seems they use the north flow when the airport is busy, and the airport is busy all the time. This renders the RUS nearly meaningless.  Last year, about 60% of all departures went over Minneapolis and we still got almost 40% of the arrival traffic also.  So, even though the runways that route traffic over Minneapolis are the last to be used on the list, we still had 50% of all operations over Minneapolis last year.

Both the MAC and the FAA have been partners in developing the RUS and we expect that they will work with us to ensure that the RUS is used and is meaningful.  We want to explore whether more operations can occur over areas in Eagan and Mendota Heights that are not heavily populated and have land use more compatible with air traffic.  Ideally, would like to reduce both departures and arrivals over Minneapolis.  That is admittedly a challenge, but we would like to ensure that the other runways are being used to their highest potential and that the use of head-to-head operations at night over Eagan and Mendota Heights are fully explored.  When runways over Minneapolis are used, we want them used in a more balanced way. We will keep you informed about these efforts and opportunities for you to help.

Another emerging issue

In addition to runway use, there are a number of airport-related issues that we are monitoring. One issue we are keeping an eye on is the “upgauging” trend. “Upgauging” refers to swapping out an airplane for a larger plane in the fleet that can carry more passengers. Airlines have expressed an interest in upgauging in order to move more people, especially at the most desirable peak times of day when people want to travel.  We are monitoring this trend to see how much upgauging is occurring, and what it means for residents in terms of the airplane altitudes and noise. It has been argued that upgauging could be a good thing because it could reduce the total number of operations (you can move the same number of people with fewer planes), however, we remain concerned about potential negative impacts.

Status of Area Navigation (RNAV)

In November of 2012, 13th Ward neighborhoods lobbied against implementation of Area Navigation (RNAV) departure tracks. RNAV is a navigation method that results in planes taking the same narrow paths consistently. The FAA sees benefits to the system; they see it as a tool to save fuel and they argue that RNAV procedures have safety benefits. Minneapolis and its residents, however, had one very serious concern: What would the impact of RNAV be for those who live under the flight tracks? When the MAC was asked to authorize the use of RNAV at MSP, resident concerns and questions had not been addressed. Together we successfully stopped the implementation of the departure tracks, which was a rather unprecedented effort.

As of yet the FAA has not returned to discuss RNAV departure tracks. We have informed the FAA that if they want to discuss the possibility of RNAV for departures, they should begin by providing examples of similarly-situated airports where RNAV has been implemented successfully. They should also expect a very robust community engagement process and they will need to provide much better information to the City and its residents. We have many strong allies, including Congressman Ellison and our State Legislators, who continue to stand with us.

Although RNAV has not been approved for departures, RNAV procedures for arriving planes (also known as STARS) will be used starting in March of 2015. Arrivals over Minneapolis are very different from departures because—when over Minneapolis—the planes are already aligned with the runway and therefore, already on a very narrow path. There are some potential benefits of RNAV for arrival tracks. The planes will use an “optimized profile descent,” which is touted as a smoother, more gradual descent that is less noisy than the stepped-down descent that is used now.

Other efforts underway

There are a number of other efforts underway that Minneapolis and our partners are actively engaged in to try to improve conditions for residents around the airport and address concerns that we have about noise and health impacts. For example, the Metropolitan Council has a role in reviewing the long term plans and capital investments of the airport.  We have encouraged the Met Council to include a more robust review and analysis of the health and environmental impacts on adjacent residents as they conduct their review. Even if the airport itself can accommodate more planes, for example, we ask the Met Council to consider whether the adjacent community can accommodate more planes.  

Another example of what is being done is that a few dozen members of Congress, including Congressman Ellison, recently sent a letter to the FAA urging them to consider adopting a noise standard of 55 decibels for the Day-Night Average Sound Level (DNL) metric instead of the current federal standard of 65 DNL.  We are hopeful that this coalition of interested U.S. Representatives represents an opportunity for more collaboration on other airport noise issues.

How can you help?

Minimizing aircraft noise will continue to be one of my priorities, and since taking office in January I have been working to address this issue. As a member of the City of Minneapolis Airport Working Group, I work on these issues with colleagues from neighboring wards to ensure that Minneapolis residents are heard. My office will continue to communicate with you about these issues and, from time to time, may ask you to take action. While there are many important issues, I will be very clear when I feel direct action is timely.

As noted above, we are asking the MAC—through the Noise Oversight Committee—to do a thorough examination of how the Runway Use System is working and determine how we can reduce the number of airplanes over Minneapolis. If you would like to write the MAC to encourage a robust review, you can contact your Commissioners here using the map at the top right of the page. We will keep you posted about how this process is going.

There are also some things on the horizon where we may need your support. The airport has begun preparing an update to their Long-Term Comprehensive Plan. The airport is anticipating substantial growth in the number of people flying in and out of MSP, and this raises many questions about how MSP plans to accommodate such growth while not adding greater burden to residents. We will need them to explain how they intend to do that.

In the meantime, if you want to follow airport related issues in greater depth I encourage you to get in touch with the MSP FairSkies Coalition (http://mspfairskies.com), a local grassroots organization that has been working on fighting airplane noise pollution. You can also report noise occurrences (particularly those late or very early) to the MAC Noise website. The more data we have, the better our argument for making changes. The number of people who make complaints is an important statistic, so even making one complaint per month is helpful to show the level of concern.

As always, please don’t hesitate to share your observations and concerns with me (especially those observations that seem out of the ordinary). I have an airport specific e-mail list for people who may want to follow these issues a little more closely. I may sometimes send messages there that are not distributed to my entire newsletter list. If you would like to be added to that list, please write to my Senior Policy Aide at emily.ziring@minneapolismn.gov.

Yours in service,