Air Traffic Noise Screen

AGENCY:

Federal Aviation Administration (FAA) DOT.

ACTION:

Notice of change in air traffic noise screen policy.

SUMMARY:

This action changes the FAA Air Traffic Noise Screen (ATNS) policy to incorporate an administrative change in the procedures to conduct the ATNS. This action is issued as a Final Notice without prior notice because this change is administrative and/or required by statute. Also, the current adoption of the policy change is in the public interest.

DATES:

Effective January 5, 2001.

FOR FURTHER INFORMATION CONTACT:

William J. Marx, Environmental Programs Division, Office of Air Traffic Airspace Management, Federal Aviation Administration, 800 Independence Ave., SW., Washington, DC 20591; Telephone: (202) 267-3705.

SUPPLEMENTARY INFORMATION:

Background

In 1987 the Federal Aviation Administration (FAA) implemented the Expanded East Coast Plan (EECP). At that time air traffic proposed actions above 3,000 feet above ground level (AGL) were considered non-controversial by nature and were categorically excluded from further environmental review under the National Environmental Policy Act of 1969. When the EECP was categorically excluded from further environmental review, populations in New Jersey reacted strongly. The action became highly controversial, and Congress mandated that an Environmental Impact Statement (EIS) be completed by the FAA. At that time, there was no precedence for analyzing noise effects from aircraft above 3,000 feet AGL.

In 1991 Air Traffic Services began the Congressionally mandated EIS of air traffic procedural actions associated with the EECP. Populations in the study area were analyzed for noticeable changes (± 5 decibels on an average annual basis) in their exposure to aircraft noise due to the EECP.

The FAA chose to model predicted change in noise exposure up to 18,000 feet AGL to insure that communities with predicted 45 decibel (dB) Day Night Level (DNL) (average aircraft noise level over a 24 hour period averaged over the course of a year) noise footprints were included in the study area. The resulting Air Traffic Noise Screen (ATNS) was created to address airspace changes that may cause controversy on environmental grounds at altitudes between 3,000 feet AGL and 18,000 feet AGL. It was a factor to be considered in determining whether actions normally categorically excluded from further environmental review should be reviewed as part of an environmental assessment because of the potential for community annoyance and reaction.

Since the EECP EIS, Air Traffic Services has used 18,000 feet AGL as the altitude ceiling when screening for potentially controversial noise exposures that could be expected from proposed air traffic actions. In 1999 the FAA's Office of Air Traffic Airspace Management initiated a scientific study of the ATNS to rigorously analyze predicted noise exposures using different altitude ceilings. Using a research and development tool, FAA analyzed data from a major airspace project and proposed alternative that reflected the largest proposed changes to the current area airspace design. The science-based study provided analysis on the difference in noise screening results by comparing results using an 18,000 feet AGL altitude ceiling with results using 10,000, 12,000, 14,000, and 16,000 feet AGL. Completed in July 1999, the results revealed equivalent predicted noise exposure values using a 10,000 feet ceiling as were predicted using a 18,000 feet ceiling. In addition, since the ATNS was implemented, proposals to change air traffic procedures have not identified 5 decibel or greater changes at altitudes above 10,000 feet AGL.

The results of this analysis confirm that an altitude cut-off of 10,000 feet AGL has materially the same predictive capability as the ATNS run to 18,000 feet AGL. The FAA has determined that the public interest is served by this action. The policy change enables the Air Traffic Service to avoid unproductive agency resource use; further, the policy change enables resource allocation to more timely analysis of environmental conditions for proposed airspace projects without changing environmental protection and consideration to affected communities.

Air Traffic Noise Screen Policy

Beyond the airport environs, aircraft following air traffic routes and procedures normally do not significantly influence the noise environment of underlying land uses. Air traffic procedures for operations over 3,000 feet AGL are normally categorically excluded from environmental assessment requirements delineated in FAA Order 1050.1, Environmental Impacts: Policies and Procedures.

At the same time, in recognition that some actions that are normally categorically excluded can be highly controversial on environmental grounds, the FAA has developed the ATNS which allows air traffic specialists and planners to evaluate potential noise impacts from proposed air traffic changes. The ATNS is a computerized noise screening procedure that provides guidance to air traffic managers in identifying air traffic changes that will increase aircraft noise exposure, and the possible need for an environmental assessment.

The ATNS will be used to evaluate proposed changes in arrival procedures between 3,000 feet and 7,000 feet and departure procedures between 3,000 and 10,000 feet AGL, for large civil jet aircraft weighing over 75,000 pounds. Where a proposed change would cause an increase in noise of 5 dB DNL or greater, FAA considers whether there are extraordinary circumstances in accordance with Order 1050.1 that warrant preparation of an environmental assessment.