• Increased public discourse, and community information flow, to resolve misperceptions and broaden awareness of the study effort and proposed actions.

• Continued study of project data and analysis, to draw all available insights and lessons from the information we have.

• Completion of the noise abatement package, so the study group can make informed judgments of whether the whole program addresses their concerns.

The chair noted that the upcoming meeting will also include the results of screening potential noise mitigation measures for applicability in Louisville. While outside the purview of this committee, study group members still need to take account of this element of the program. The mitigation package will determine what relief – buyout, insulation, tax credit, easement, etc – can be applied in those areas still incompatible after abatement.

Returning to the needs of the abatement program listed above, the committee recalled several neighborhood, advocacy group, and various committee meetings held since the last study group meeting to increase public awareness and attract feedback. Airport management continues to work with community leaders to clarify and refine measures under consideration. Increased involvement in the study group and its committees has added perspective at the working level. All these efforts must continue, and expand, if our program is to emerge as a consensus Louisville product that does the best possible job of addressing all concerns.

On the second point, the chair circulated as an example of continued local study a graphic produced within the study group that shows the distribution of affected residents under current and proposed conditions. This picture helps overcome the impression of disparity a plain contour map gives, by adding 2000 census data to each lobe of the contours. This gives concrete form to the concept of taking local population density, not just geography, into account, and focuses on the real objective – minimizing noise impact on people.

Completing the proposed noise abatement program is the most critical element to address remaining community and operational concerns, so the committee turned to a review of the study group chair's memorandum of 25 January laying out the remaining requirements. Beyond final modeling refinements, this memo lists six major tasks from the study group's original strategies that still require development and documentation:

• standardized arrival and departure procedures

• refined flight paths, and stipulations on their use

• navigational standards

• methods and metrics for accumulating data and evaluating operations

• management and oversight measures, structural (e.g., maintain an airport noise office) and functional (e.g., acquire flight tracking hardware and software)

• 'emerging' measures for future consideration, as policy and technology evolve

Participants recognized the importance of fully developed measures under each item for a completed noise abatement strategy for the next study group meeting. With the first three tasks clearly falling within its scope, the committee took account of these in reverse order. Members recalled, first, that supplemental consulting work has already established distances within which differently equipped aircraft in the SDF fleet should be able to fly assigned flight tracks. We anticipate these figures can be adapted for use in the abatement package as benchmarks for monitoring the fleet's fidelity to adhere to assigned tracks over time.

The second item required the committee to review proposed flight track maps against study group objectives laid out in its original noise abatement strategy and reiterated subsequently. Refinements to these tracks have been regularly discussed in general terms, and some already incorporated, but most deferred until now to permit concentration on other measures directly impacting model results. Pending their completion, these tracks have not been formally presented to the study group, nor incorporated in study documentation to date. Finishing this job is one of the most critical elements of addressing the concerns of areas of the community that lie outside the critical contours produced by the noise model.

The committee looked at each map addressing individual runway operations in turn. Potential adjustments addressed the objectives of minimizing overflights of residential areas, following where possible low-impact corridors like the river and major highways. Resulting rough map mark-ups are attached to these notes. In each case where a track has been modified in black, the corresponding prior track has been blotted out in white.

• Southbound departures: A slight adjustment to flight tracks turning to the northeast could intercept the Louisville VORTAC at an angle that would subsequently follow I-265. In turn, modestly extending those turning northwest would permit them to follow the river corridor.

• Northbound departures: The departure track for runway 35L hasn't been fully articulated, so refinements are required in any case to meet the objectives noted. This track needs an initial straight segment to align it to the offset arrival track (as we understand was done in actual modeling). A subsequent release point at the river would permit the track to divide between a westbound segment following I-64, and a northbound segment following Grant Line Road. The latter would divide again at I-265 to permit eastbound traffic to follow that highway. The track for 35R has been refined in previous work with segments aligned to the river and I-65; one small further adjustment would align the westbound segment to the river corridor as well.

• Southbound arrivals: Realigned to a one-mile centerline intercept (as we understand was done in actual modeling), the offset approach to runway 17R could have its final approach fix at the river near the intersection of I-64 and I-264. Segments preceding that fix could use the highway corridors shown in southern Indiana. A similar fix for 17L would permit minor adjustments to approach tracks from the southeast and southwest to follow the river corridor and I-264, respectively.

• Northbound arrivals: Modified turning radii from the east and west would enable approaching aircraft to use the I-265 and river corridors, respectively.

• Westbounds: A very small shift in departure tracks would orient this traffic directly over I-264, as we think was intended. A waypoint extended to the river would also delay dispersal of paths until clear of residential areas.

• Eastbounds: No changes proposed. Rare use doesn't appear to justify exceptional measures.

Members agreed to reflect on these refinements for another week, and communicate any further ideas to the chair to circulate to the committee, then go forward to the study group chair, and thence the consultants, to incorporate the results into the analysis.

The committee finally turned its attention to the development of standardized approach and departure procedures around which the FAA can design and publish specific instruction sheets, or 'plates,' for airport users. While no school-trained designers were present at this meeting, enough have been heard from on previous occasions to suggest essential elements that need to be included in developing these procedures:

• Altitude and glide slope specifications should provide the maximum noise benefit consistent with safe operations. A 3° (or at most 3.5°) descent is the safe standard regularly cited for arrivals, and is the value assumed for modeling. But our current published procedures often involve something less, and provide for routine exceptions that are much less. These are the likely sources of many of the airport's frequent complaints of "low-flying" overflights outside the contour areas. Standard approaches should preserve a 3–3.5° slope from altitudes of at least 5000 feet, and eliminate non-emergency exceptions.

• Flight paths that minimize impact on populated areas (as described earlier) should be laid out in standard approach and departure procedures, and marked insofar as possible by navigational fixes and waypoints for maximum consistency. Radar headings should be employed only to keep aircraft not otherwise equipped on the paths described, with whatever course corrections are necessary to account for weather conditions or other factors. Altitude and distance parameters noted above should be specified for the appropriate points along each path.

• Standard approaches and departures should be, well, standardized. Routing instructions should make careful stipulations on visual and other deviations to avoid unprogrammed and unnecessary noise impact. Visual clearance, for example, should only be available after an arriving aircraft reaches its final approach fix. Departure vectors, likewise, should be expected only after an aircraft passes the appropriate waypoint, and then should continue to follow the specified path.

• Noise abatement procedures should be indicated for each standard approach and departure. A 'decelerating' approach formulated in recent years, for example, appears to have considerable promise in the Louisville case. For departures, distant-oriented procedures seem appropriate for runways 17L, 17R, and 35L, while close-in procedures should apply to 17R, 11, and 29. Hypotheses like these should be validated, and the results incorporated in published instructions.

With the amount of work remaining to complete the noise abatement package, plus a review and screening of potential mitigation measures, committee members noted that meeting #6 will be a complex undertaking. The chair proposed that the several weeks available before the meeting should be used to collect and study advance material from elements already completed. Program managers have been asked to coordinate such a flow from the consulting team. The chair will distribute such material as it arrives, and propose additional committee meetings as required to address any problems or concerns. Barring these, the next committee meeting should be held shortly after Study Group Meeting #6, to review the formal presentation and develop recommendations.

The meeting adjourned at 9:30 PM.

back to top