In a marked change in longtime Federal Aviation Administration (“FAA”) policy regarding analysis of noise and air quality impacts from FAA initiated, directed or funded projects, FAA has substituted a single new model for the long mandated Integrated Noise Model (“INM”) and Emissions and Dispersion Modeling System (“EDMS”).  Beginning May 29, 2015, FAA policy “requires” the use of the Aviation Environmental Design Tool version 2b (“AEDT 2b”), which integrates analysis of aircraft noise, air pollutant emissions, and fuel burn.  These impacts, according to FAA are “interdependent and occur simultaneously throughout all phases of flight.”  80 Fed.Reg. 27853.  

The FAA policy provides for differential displacement of existing analytic models.  For air traffic and airspace procedural changes, AEDT 2b replaces AEDT 2a, already in use.  For other, ground based projects, AEDT 2b replaces both the INM, for analyzing aircraft noise, and EDMS for developing emissions inventories and modeling emissions dispersion.  The change was presaged by FAA Administrator Michael Huerta who announced in April that FAA was undertaking an “ambitious project” to revamp its approach to measuring noise.  The “ambitious project” was apparently inspired by the vocal objections to the results of the analysis using current methodologies, voiced by citizens of locals that have experienced the effects of FAA’s current, nationwide reorganization of airspace around major airports to institute procedures based on Performance Based Navigation (“PBN”).  

In Phoenix, for example, the community is up in arms over the narrowing of flight tracks that result from the PBN procedures.  The consolidation of flight tracks places the full complement of aircraft over a much smaller geographic area, thus moving and geometrically increasing the noise over those areas, some of which were never previously overflown.  The next place for the controversy to play out will be in Southern California.  FAA intends to launch the environmental review for its soon to be initiated Optimization of Airspace & Procedures in the Southern California Metroplex (“SoCal Metroplex”) project which will realign the airspace over eight airports in the Southern California Region.  The new AEDT 2b methodology will arguably apply to these new environmental analyses which are being commenced after its May 29th initiation date of applicability.  The impact of the new methodology on analytic results, and the way in which those results compare to those that would have been generated by INM and EDMS remain to be seen.  What is certain is that impacted populations and their noise and air quality consultants should make that determination at the earliest time in order to be able to adequately evaluate the true analytic impacts of FAA’s new model AEDT 2b.