Good Progress at Phoenix, but should the FAA find a new noise metric

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Phoenix legal defeat prompts FAA to address noise concerns


The FAA has responded well to its embarrassing Court Decision and the AP reports on the current status of the implementation of NextGen AT procedures in Phoenix:

PHOENIX (AP) — Nearly 100 people strolled through the high school cafeteria throughout the evening, studying colored graphs of 
flight takeoffs and jotting down comments for officials.

More than three years after they awoke to find window-rattling flights rerouted in an airborne highway above their homes, 
residents of Phoenix's downtown historic districts said they finally felt the Federal Aviation Administration was listening.

A court victory by Phoenix and neighborhood groups over the FAA last year has prompted the agency to be more responsive to 
residents as it continues to beat back noise complaints around the United States over the air traffic modernization plan 
known as "NextGen."

While challenges by residents of Washington's Georgetown neighborhood and other jurisdictions are still being heard in court, 
people in other affected areas such as Santa Cruz, California, have not sued the agency because they believe their complaints 
are being considered. Phoenix residents said they appreciated the FAA's current approach.

"They are being transparent now," Opal Wagner, a resident of the vintage Willo district and vice president of the Phoenix Historic 
Neighborhoods Coalition, said at the first of three FAA public workshops held last week. She and others expressed disappointment 
that a fourth one wasn't scheduled downtown where most noise complaints originated.

"I think that it's good that they are now dialoguing with the public," Wagner said. "Maybe if they had done this in the beginning, 
there wouldn't have been a lawsuit."


The rollout of the procedures in Phoenix initially represented NextGen's "most problematic implementation," said Chris Oswald, 
vice president of safety and regulatory affairs with Airports Council International-North America, a trade association that 
represents commercial airports in the U.S. and Canada. He said he was cautiously optimistic about the FAA's more open approach.

In the Phoenix case, the U.S. Court of Appeals for the District of Columbia Circuit on Aug. 29 agreed with the city and historic 
districts that the FAA was "arbitrary and capricious" in its flight procedure revisions in that area. The court said by leaving 
people in the dark, the agency made it impossible for the public to express views on the project's potential effects — something 
the FAA is especially required to do for historic places and parks.

Phoenix residents said they received no forewarning about the flight changes after FAA officials determined they would have no 
adverse impact and claimed a "categorical exclusion."

Following the court ruling, Phoenix and the FAA on Nov. 30 announced a joint plan aimed at resolving the dispute. Under the plan 
filed with the appellate court, the FAA agreed to reach out to residents while temporarily resuming the previous departure routes 
starting April 1.

In a second step, it will develop satellite-based procedures for the original routes, seeking community feedback throughout the process.

"I think we will get a considerable amount of relief with the return of the flights to their previous paths," said Brent Kleinman, 
president of the Encanto-Palmcroft Historic Preservation Association in central Phoenix.

"But the majority of the work is going to be in the second part of the process," he said, which will decide the final flight paths.

During last week's workshops, Phoenix residents received printed material and mingled with FAA environmental experts and the airspace 
designers who fashion flight paths.

"This is a format that we've used at other workshops, and it works really well," said Ian Gregor, public affairs manager for the 
FAA's Pacific Division, who attended all three sessions. "The people who have actually designed these procedures are on hand to answer 


Phoenix’s Battle with FAA’s NextGen ATC implementation requires expert knowledge of the science and art of design


Out of the Ashes of the DC Circuit Court on the NEPA review of the FAA NextGen at PHX implementation, some better approach must RISE


Phoenix parties and FAA offer a new win/win NextGen option?



A better approach to dealing with the community and designing flight patterns which should limit opposition are good, but there may be an underlying technical problem.

NextGen Noise: RNP’s concentrated IMPACT may justify substantive change in FAA policies under a proper study —link

Posted By: Cynthia Schultz December 28, 2015


Aviation noise is being heard and objected to in higher volumes than in the past. It is hard to quantify the level of negative reactions in the metrics of engineering measurement, but the qualitative response is hard to ignore.

→ Where are the complaints being registered? As evidenced by the below two articles and numerous other reports, citizens in


  • Boston,
  • Charlotte,
  • Chicago,
  • New York,
  • Phoenix,
  • San Diego,
  • San Francisco,
  • Seattle
  • Washington, DC and
  • Other places

are vociferously making their objections known.

→ What do these cities have in common? As shown by the FAA website on NextGen, all of these airports have implemented NextGen procedures.


→ What can be gleaned from looking at these noise patterns? There is both good news and bad news.

  • The environment on a macro basis is better off; because the generalized area of impact is significantly decreased.
  • There is also BAD NEWS on a micro basis; in that the precision of the RNP technology and implementation CONCENTRATES THE NOISE IN A SMALLER AREA. The residents in these areas may be experiencing substantial increases over their historic noise levels (+10 points on the scale equals a doubling of the loudness). Further, the RNP addition to the noise may not reach the FAA’s long standing threshold of 65 dBA; so the NEPA review may find that this change does not preclude the implementation. What sets the DNL “energy average” apart from a mathematical average is that for every increase of 10 dBA in a noise level, the energy is increased by a factor of 10. For example, an event of 70 dBA contains 10 times the energy of an event of 60 dBA or one hundred times the energy of an event of 50 dBA.

So the people living under these new HIGH TECH, GREENER flight patterns are told at the end of the FAA study that there will be “no significant impact,” a term of NEPA art, which certainly infuriate the affected citizens.

→ What has Congress conjured up to address this situation? The elected representatives have proposed reopening the ATC review process; see FAA Community Accountability Act of 2015 (FCAA). First, it should be noted that Congress recently reduced the review requirement for the FAA in implementing NextGen flight patterns (H.R.658 — 112th Congress (2011-2012), the FAA Modernization and Reform Act of 2012 (FMRA)). There is little likelihood that there will be a different outcome under an enacted FCAA by

  • ordering the FAA to RECONSIDER its previous determination
  • under the FCAA rubric, the process would entail a comparison of the original efficient, safe architecture vs. an alternative designed without the necessary expertise
  • under the original NEPA standard,
  • adding an ombudsman,
  • placing the airport explicitly in the process and
  • little else.

What the Congress has failed to realize is that the average citizen noise group needs significant resources to do anything other than say NO to the FAA RNP proposal. They need more than a new process; they need technical expertise to offer acceptable options.

→ What is the FAA doing? In a March 27, 2015 letter from Administrator Huerta to a coalition of aviation associations, he announced an “ambitious project to update the scientific evidence of the relationship between aircraft noise exposure and its impact on communities around airports in today’s context of quieter aircraft, but with more aircraft operations than in the 1980s and 1990s and heightened environment awareness.” The letter noted that the study was specifically in response to implementation of PBN tracks. The precise nature of the FAA studied was outlined in the Administrator’s letter:

The data from such a loosely defined and gathered study does not appear to determine the precise impacts of the RNP concentrated procedures and hardly seems to be compelling enough to justify any changes in the FAA’s historic standards. {Rather tellingly, the letter invites replies NOT to the FAA technical environmental staff, but its Congressional relations office.}

→ What needs to be done?

  • The predicted noise levels of select Environmental Assessments (perhaps Phoenix) need to be verified by actual noise measurements within the new PBN flight corridors to determine why the reaction to noise impact is so much greater than the predicted noise impact.
  • If the predicted noise impact is found to be accurate through physical noise measurements, then the threshold for significant impact needs to be evaluated and adjusted to account for factors such as aircraft operation frequency and differing community tolerance for noise.
  • As illustrated above the issue of frequency may not have a significant impact on the DNL value but certainly appears to be having an impact on community tolerance of noise. The current FAA threshold of significance (1.5 Db at 65 DNL and above) does not account for the significant increase in frequency that occurs under the new PBN corridors.

While this noise assessment may take longer than the FAA’s phone survey of citizen perceptions, the results of a technical review are FAR MORE LIKELY TO JUSTIFY A SIGNIFICANT CHANGE IN POLICY.




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