Guest Commentary: Take advantage of FAA’s extended comment period on jet noise standards and mitigation

How to measure the community impact of aircraft noise is part of the FAA’s Noise Policy Review.
(K.C. Alfred / The San Diego Union-Tribune)

This is an update from our May report regarding the efforts to reduce commercial jet noise over impacted San Diego communities.

The prior deadline of July 31 to submit comments to the Federal Aviation Administration on jet noise standards and mitigation has been extended until Friday, Sept. 29.

In 2017, the FAA began to implement the NextGen Southern California Metroplex Project, which modified commercial flight patterns to and from San Diego International Airport to optimize the efficiency of airspace use. This led to a further concentration of flights, or “highways in the sky,” above several San Diego communities.

Scientific research ( and other data indicate that concentrated exposure to repetitive jet noise causes serious medical harm, including cardiovascular events like stroke and heart disease, cognitive processing problems such as decreased school performance for children, sleep disturbances and increased stress. Similarly, small-particle jet emissions are linked to serious human diseases like respiratory ailments and even to premature death.

Dispersing jet noise and particle emissions is an acknowledged antidote to concentration and is defined as “the process of introducing track variability by changing aircraft lateral position enough to spread out repetitive and intrusive noise events experienced by people living under highly concentrated flight paths” (UC Davis Aviation Noise and Emissions Symposium, February 2021).

Don Scata, the FAA’s director of noise research and policy, gave the keynote address at the recent Air Noise and Emissions Symposium in April. He acknowledged that the FAA has received many more noise complaints after it rolled out the NextGen concentrated flight paths nationwide. He noted the significant noise impact on “flight corridor communities” and that the FAA’s recent Neighborhood Environmental Survey reported a significant increase in annoyance complaints.

Scata announced that the FAA is open to considering additional metrics to measure noise levels and reassess thresholds, including modifying the level at which the FAA considers noise to be “normally compatible” or of “insignificant impact.”

A key question is how to measure the impact of aircraft noise on residents and communities. The FAA has traditionally used a decibel threshold, but recent research suggests that measuring the frequency of noise events is a more accurate metric of human annoyance, stress and resulting health consequences. While one overflight at 65 decibels may not bother you, 10 overflights in 30 minutes is another story.

Noise experts recommend using a standard that measures noise repetition and frequency, or the “N above” standard, i.e., assessing the number of noise “doses” above a threshold after which noise becomes a significant stressor.

The FAA opened a comment period for its Noise Policy Review, which will evaluate:

• Whether the current use of the “day-night average sound level,” or DNL, should be the primary noise metric for assessing cumulative aircraft noise exposure

• If and how alternative noise metrics may be used in place of or in addition to DNL

• The community’s understanding of noise impacts and how to better respond to aviation noise concerns

• The findings of ongoing noise research and more

On July 10, the FAA granted an extension until Sept. 29 for the public to comment on the Noise Policy Review. The extension comes at the request of the Aviation-Impacted Communities Alliance’s 71 members, including San Diego. To comment, visit

We urge all affected areas of San Diego to submit comments by the extended deadline and that the San Diego County Regional Airport Authority sponsor and facilitate roundtable meetings to encourage a unified voice from San Diego. We appreciate the strong support we have received and reiterate that San Diego can achieve optimal results working together as a community.

Aviation-Impacted Communities Alliance

After the FAA rolled out its NextGen navigation program in 2016-17, communities across the country united under the Quiet Skies organization and a congressional caucus, advocating nationally for the FAA to roll back NextGen and/or mitigate the human health harms it causes.

Many have joined the Aviation-Impacted Communities Alliance, or AICA, to pool resources, coordinate efforts and work at the national level for change. As the Airport Noise Report wrote: “In past years community groups have acted individually to get noise issues of concern addressed in FAA reauthorization bills. This is the first year the ANR has seen a large coalition of community groups speaking to Congress with one voice.”

AICA is lobbying on Capitol Hill for solutions to address noise in communities more than a mile from airports (that are not within the 65-decibel day-night average sound level contours), require the FAA to take advice from the National Academy of Sciences on human health impacts from commercial jet noise, and require the FAA to devise action plans to alleviate noise and address community concerns, among others.

No single solution will work for all airports because geography, traffic constraints and external factors will require local answers. Flight dispersion and making use of the Pacific Ocean, however, are winning concepts for the entire greater San Diego community and should be implemented at the San Diego airport.

Trying to fix what’s broken

The NextGen project concentrated departures and landings over tight corridors, resulting in repetitive noise exposures to previously quiet communities.

Communities affected by the concentrated departure paths include La Jolla, Mission Beach, Ocean Beach, Pacific Beach and Point Loma, all of which are central to San Diego’s tourism interests. These communities participated in a series of meetings and workshops with the goal of recommending noise abatement and mitigation procedures to the FAA. Proposals were made to disperse noise across three departure tracks so that no single community or group of residents bears a disproportionate burden of living under or adjacent to a flight path.

The communities failed to come to an agreement about where to locate the three recommended dispersed flight tracks. Although the dispersion proposal would have reduced noise for thousands of residents (mostly in Mission Beach, Ocean Beach and Point Loma), a slight shift in noise would have affected a dozen or so homes in Ocean Beach.

The airport declined to move forward without unanimity. However, it committed to reevaluate the dispersion proposal in 2026, and it is important that all San Diego communities collaborate and reach a consensus on a solution that provides a win for the entire region.

Dr. Matthew Price, Chris McCann and Anthony Stiegler are co-founders of Quiet Skies La Jolla and San Diego.