January 25, 2002
MEMORANDUM
TO: Bob Brown, RAA Project Manager
FROM: 150 Study Group/Mike Clancey, Chair
SUBJECT: Noise Abatement Strategy
The Study Group’s last formal meeting, 5A, of October 18 was intended to achieve consensus on selected noise abatement measures. These were mainly runway use alternatives and close-in approach and departure paths our consultants had analyzed by computer simulation. Because some participants in that meeting raised a number of concerns and reservations, I called a pause in our proceedings, so the Study Group could address these issues. For the last three months, we’ve conducted additional neighborhood and committee meetings to clarify these concerns. Also, we have had new members from various neighborhoods, and they have added their thoughts to the process. We’ve collected and assessed additional data on the alternatives and their impacts. And we’ve considered how remaining reservations might be addressed, either by modifying existing measures, or by incorporating other measures the Study Group has adopted, but that have not yet been developed and analyzed.
At this point, I think we’re ready to move ahead. Several new interested parties have signed up for future committee work, and will be adding their perspectives to the ongoing effort. Further data and analysis have added depth to Study Group insights gained to date. Added questions have been framed that need professional treatment.
Modeling to date seems to have done the best possible job of minimizing population within critical noise contours. Only one concrete proposal has been put forward to improve the effectiveness of the modeled measures. Air traffic controllers have noted that the mid- to late-morning period is systematically dominated by arrivals, so an incremental benefit could be realized by favoring north flow during this period, as we do during the ‘arrival push’ at night. The pattern is well substantiated by existing study data on arrivals and departures by time of day.
We therefore propose to incorporate in final modeling a measure that would reflect preference for north flow between 9:30 AM and 12:30 PM. This modeling should otherwise depict preferential use of the west runway for operations north of the airfield (as in "alternative 3"), and current divergence procedures for departures south of the airfield (as in "alternative 1"), along with the full package of common measures previously modeled.
One further operational measure proposed by the consultants and adopted by the Study Group, but not yet represented in modeling, is a displaced arrival threshold for runway 17R. The sensitivities of stakeholders northwest of the airfield make it far too early to take this measure off the table, airport staff assertions of high implementation costs notwithstanding. As a minimum, consultants should show representative effects of this measure on the preferred alternative, rather than the base case, since the dynamics of such a measure are clearly different with an offset flight path.
What will determine whether consensus can be preserved on measures laid out so far is the balance of the noise abatement package. Most of the key concerns still on the table are properly addressed by measures included in the Study Group’s package of 14 Feb 2000, but not yet developed or documented in finished form. That’s the reason they’re still on the table – not because the modeled measures are flawed or inadequate. It is therefore imperative that the preferred alternative the consultants present in the next formal meeting be a complete noise abatement strategy. This would include, at minimum, the following additional elements:
• Develop noise-optimal STARs and SIDs to minimize impact of overflights on Louisville airspace, especially in densely populated or elevated areas.
• Refine approach and departure plates to incorporate prescribed glide slopes; maneuvering altitudes; noise abatement procedures; and fixed flight paths, except in emergencies, or where FAA regulations prohibit.
• Design RNP standards for monitoring fidelity of air traffic to prescribed flight paths.
• Design cumulative event metrics for monitoring contribution of individual users to overall noise exposure.
• Lay out management measures package for review and implementation, to include the Regional Airport Authority’s acquisition of an Airport Noise Management System.
• Document 'emerging' measures (in outline, at this point) for future consideration.
The critical challenge at this juncture is to put before the Study Group the full array of abatement measures, as well as proposed mitigation measures, so that members can make an informed judgment of how effectively their issues have been addressed. That will permit us to seek consensus to move ahead on the basis of complete information. Our efforts can then concentrate on what changes or refinements are possible and appropriate, rather than deferring concerns to later developments.
Our task only grows more complex as elements are added, and the accumulation is now approaching its peak. We must take extreme care at this point to maintain clarity, precision and focus on our objectives and the contribution each element makes. It’s therefore essential for us to keep the lines of communication open and flowing for us to meet our objectives.
Should any of the Study Group’s noise abatement measures require elaboration beyond that provided already, please contact me without hesitation. We look forward to your consultation in moving this process forward.
February 8, 2002
Bill Willkie
Leigh Fisher Associates
PO Box 8007
San Francisco Intl Airport
San Francisco, California 94128-8007
Subject: P150 Update
Teleconference of 2/1/02
Dear Sir,
This letter is to confirm our direction and position on the issues submitted with the Study Group’s memo of January 25, and my letter of January 28, all as discussed in our teleconference on February 1, 2002.
1. Reverse Flow Information
Bob Slattery is compiling information to supply to you for input into the model. This information will consist of a listing of regular arrivals and departures during weekdays from 9:30 AM to 12:30 PM to allow "Reverse Flow".
This information will be run in the model. A second run without the "Reverse Flow" will not be run unless the Federal Aviation Administration requires it.
2. Displaced Threshold
It was agreed in the teleconference that the displaced thresholds have minimal benefit with regard to noise levels in the base case. Leigh Fisher will present in Meeting #6 a description, to be included in the NCP, of this measure and its potential benefit to the preferred alternative, and compare that case to estimated costs. Anticipating that costs will probably outweigh benefits of this measure, the displaced thresholds will not be modeled as part of the preferred alternative presented at Meeting #6.
3. STARS and SIDS
Leigh Fisher will develop (i.e., lay out necessary parameters) and write up proposals for submission, in the NCP, to the Federal Aviation Administration. It is the Federal Aviation Administration’s responsibility to design and publish STARS and SIDS.
Related to this issue, flight tracks beyond the study area (e.g. over Floyd’s Knobs) will be described in the NCP but again it is up to the Federal Aviation Administration to design fixes etc. to enable aircraft to fly these tracks.
4. Approach and Departure Plates
Approaches and departures are designed by the Federal Aviation Administration, and will not be composed by LFA. The NCP will recommend that maximum glide slope angles appropriate criteria and procedures to be included in design of these approaches and departures.
5. Design RNP Standards
RNP standards are a level of precision that a particular aircraft can use to stay on prescribed flight tracks. LFA will lay out the standards used for modeling each of the aircraft types in the SDF forecast fleet, and make recommendations for applying these standards for performance monitoring and oversight. Leigh Fisher will state in the NCP, that the flight tracks used in the preferred alternative assume use of these RNP standards.
6. Cumulative Event Metrics
This issue has evolved from the original objective of defining "limits" to one of just facilitating monitoring and oversight . Leigh Fisher will make recommendations for conformance monitoring as a deliverable in the NCP.
7. Management Measures
Leigh Fisher will make recommendations in the NCP on organizational and analytical measures management should take to monitor, record or control noise in the airport environs.
8. Document Emerging Measures
Leigh Fisher will write up a discussion of emerging measures in the NCP for follow on work by the Regional Airport Authority management/community after the NCP is approved.
9. Offset Approach
Bob Slattery will check on what airlines have agreed, or disagreed, to flying the offset approach. Leigh Fisher will run the preferred alternative with the resulting airlines we specify using that approach.
As we discussed a two weeks ago, the Study Group’s memo is part of the documentation to be attached to the NCP. This letter should be appended to that document.
If you have any questions, please contact myself or Bob Slattery.
Sincerely,
Robert A. Brown P.E., L.S.
Director of Engineering
cc: Jim DeLong
Dorn Crawford
Bob Slattery
Mary Rose Evans
Mike Clancey