Noise Abatement Strategies
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February 14, 2000
TO: LFA/Bill Willkie, Project Manager
FROM: 150 Study Group/Lt Col Tom Marks, Chair
SUBJECT: Noise Abatement Strategies
The attached noise abatement strategies are a consolidation of measures approved for analysis by the 150 Study Group at its February 3 meeting, based on suggestions from your October 15 presentation; refinements or additions put forward by the Study Groups various committees and adopted on December 7; and feedback furnished in your presentation of January 13.
The Study Group is guided, as before, by its aims to:
reduce noise contours
The discussion attached here is an effort to make a complete account and disposition of measures previously adopted, and lay out an experimental design that achieves the most robust coverage for the resources available. But the Study Group fully recognizes the criticality of this phase of the study; so its important to emphasize some key aspects of near-term activity that will make or break the effort. These include:
Precise, mutually understood composition of each strategy. To insure fidelity of the design and implications of results, no uncertainties should remain about measures included or excluded; how measures are represented for analysis; or interdependencies arising in the analysis. Rationale must remain clear throughout, and follow-on documentation planned and previewed to preserve the consensus of the group.
Open-ended review of results. Broad discussion of the substance and implications of the analysis are essential to an enriched package that directs results to specific local needs. Assumptions and conclusions must be challenged at every turn to confirm their rigor, with ongoing feedback directed to refining and improving them.
In short, work in this phase is crucial to study results. "Oops" is consequently no longer an affordable part of the vocabulary.
Minimize contraflow exceptions. Postulate procedures that would direct scheduled flights during contraflow periods into conforming patterns, by rescheduling; leveraging the interim between arrival and departure periods; proposing additional pauses during these periods; or other means to direct all operations but emergencies to the south during the contraflow period.
Determine and apply noise-optimal prescribed flight tracks (STARs, SIDs) for all six runways (11, 17L, 17R, 29, 35L, 35R). Combine detailed knowledge of practical flight operations and local population distribution to plot routes for arrivals and departures that yield minimum noise exposure to populated areas. Observe currently prescribed minimum runway divergences, except where otherwise indicated below. Incorporate considerations of simultaneous operations; elevation of affected neighborhoods; and restricted airspace around Fort Knox. Provide for minimal exceptions from prescribed tracks, in cases of pilot-declared emergency, weather extremes and the like.
Apply required navigational performance standards (RNP), or hardware specifications, to minimize deviation from prescribed flight tracks. Develop and apply the strictest standard that can reasonably be imposed on users of the airport with available technology to insure fidelity to prescribed routes.
Operational measures (potential excursions). Apply such constraints as are necessary to insure that prescribed flight tracks are used consistently in non-emergency situations, and to the best effect. Visual approach clearances, for example, should not permit deviation from prescribed tracks, but only add flexibility to factors like delayed flap and gear extension that would further reduce noise exposure. Thrust procedures, if practicable, should be applied uniformly, to avoid complicating the tasks of pilots using the airport.
Higher holding and maneuver altitudes, in particular as required to compensate for increased elevation of selected areas
Facilities, use restrictions, and regulatory measures. Specific measures endorsed by the Study Group include
Postulate placement and use of whatever navigational aids are necessary to support arrival and departure tracks (STARs, SIDs) developed above
Establish airport noise office
Document knowledge of emerging measures. Education of all affected constituencies, and a robust implementation program poised to take advantage of new developments, are central goals of the study effort. Its therefore important that study reporting include all available information on any measures deferred in the present program because of practical or technological developments that are not yet mature. This knowledge base will permit orderly revisitation and further consideration of these measures as their maturation warrants. Specific measures endorsed by the Study Group that preliminary assessment places in this category include:
Advanced navigation aids (laser homing, microwave landing systems, military-specification GPS equipment, "ADS-B")
Limit east runway preference to daytime only. For modeling, retain current runway use frequencies during the day (7AM10PM), but change nighttime frequencies to approximate equal use of both runways. Make initial array based on destination; advise if further steps necessary to achieve parity. Manipulate STARs and SIDs to minimize noise exposure of affected populations.
Eliminate runway preference entirely. For modeling, change frequencies to approximate equal use of both runways. Advise operational steps needed to achieve parity, if any, beyond runway assignment by destination. Manipulate STARs and SIDs to minimize noise exposure of affected populations.
Reverse runway preference. For modeling, reverse current runway use frequencies. Manipulate STARs and SIDs to minimize noise exposure of affected populations.
Measures deferred or dropped
Many of the measures previously endorsed by the Study Group in the categories of flight tracks, approach and departure procedures are now embedded in the central aim of determining and applying optimal flight tracks. These would therefore no longer need separate treatment:
Uniform turning criteria
Selected measures characterized as "voluntary" should be carried forward, but not represented in modeling, since their effects cant be forecast with confidence:
Delayed flap and gear extensions
Measures already applied, and requiring no apparent further action:
High-speed exit taxiways
Measures for which the Study Group accepted consultant recommendations against, or could not achieve consensus to pursue, and which are therefore excluded from the strategies outlined above:
Reverse thrust restrictions
Measures appearing to lie beyond the capacity of model-supported analysis, omitted from strategies outlined here but reserved for further treatment elsewhere in the study:
Show effect of full conformance to current noise compatibility program
The preceding is intended to represent a complete account of the measures put forward by the Study Group in its 10 December 1999 consolidation. Please advise of any apparent lapse, or other suggestions.