NEW Noise Mitigation Boundary Maps
Land Use Study Project
A noise mitigation measure undertaken by San Antonio International Airport (SAT) was a Land Use and Development Plan awarded to Llewelyn-Davies Sahni (LDS) in June 2003 for a comprehensive Land Use Study around San Antonio International (SAT) and Stinson Municipal airports (SSF). This study involves many phases and analyses the current land uses and zoning surrounding each airport. The completed steps include an inventory of current land uses and the first round of public workshops. They are continuing to develop strategies for land use and acquisition with an estimated completion date of September 2005
SAT has established an Airport Awareness Zone which is a boundary whereby proposed zoning changes around San Antonio International and Stinson Municipal Airports need to be reviewed to help maintain compatible uses.
SAT Runway Usage
San Antonio International Airport(SAT) Runway use is determined by several factors including safety, weather, traffic demand, runway capacity, aircraft destination, runway length requirements, and prescribed runway use procedures. Air Traffic Control (ATC) assigns runway (RWY) use with consideration to all of these factors. Capacity needs at SAT require ATC to utilize at least two runways (RWY 12R/30L, 3/21) during much of the day. However, wind and weather conditions will help determine which flow pattern is used.
Noise and Operations Monitoring System (NOMS)
San Antonio International Airport (SAT) has installed a Noise and Operations Monitoring System (NOMS) which collects noise and flight tracking data. The Computer system and sensors utilizes the AirScene hardware and software. This computer system consists of 12 Remote Monitoring Sensors RMS) and 5 Multilateration flight tracking sensors in communities surrounding the airport.
The NOMS monitors aircraft over-flying local communities and notes their noise levels. Each monitoring site is linked to a central computer processor and is constantly updated with the latest flight, weather, radio communications and noise data. The NOMS was installed by Rannoch Corporation during 2004 and 2005 to provide noise and flight tracking data to the Noise mitigation office. The NOMS provides an objective tool for assessing and analyzing airport noise impacts and airspace utilization.
The NOMS data is used to:
• Record aircraft noise events
• Track noise levels over time
• Assess adherence to noise abatement flight paths
• Link complaints to flights, airlines and aircraft types
• Map complaints
• Validate the accuracy of computer created noise maps
• Create reports
• Produce maps and graphics
Because it is important to be able to relay to the local communities the level and nature of the noise in a timely fashion, the Aviation Department has this permanent noise monitoring system to monitor the areas of significant noise impact and identifies specific flights that cause noise disturbances.
Since Noise is a problem at every airport. This tool allows real time tracking and reporting of compliance with published noise abatement procedures. Aircraft deviations are noted by identity, magnitude of deviation, and correlated with pilot/controller voice communications for a case-by-case analysis.
Noise Abatement Departure Profiles
FAA AC91-53A was published to provide guidance to commercial aircraft for development of voluntary standardized Noise Abatement Departure Procedures (NADPs) for subsonic turbojet airplanes with a max takeoff weight exceeding 75,000 pounds.
The Airport has signs that request voluntary use of the close-in NADP
SAT conducted live testing of the two FAA approved procedures (Close-in, Distant) and
Tests determined that there was some noise relief with the use of close-in procedures.
The Close-in NADP consists of initiating a thrust cutback at an altitude of no less than 800 feet AFE and prior to initiation of flaps or slats retraction.. The thrust cutback may be made by manual throttle reduction or by approved automat& means. The automatic means may be armed prior to takeoff for cutback at or above 800 feet AFE or may be pilot initiated at or above 800 feet APE.
For airplanes without an operational automatic thrust restoration system, achieve and maintain no less than the thrust level necessary after thrust reduction to maintain, for the flaps/slats configuration of the airplane, the takeoff path engine-inoperative climb gradients specified in FAR Section 25.111(c)(3) in the event of an engine failure.
For airplanes with an operational automatic thrust restoration system, achieve and maintain no less than the thrust level necessary after thrust reduction to maintain, for the flaps/slats configuration of the airplane, a takeoff path engine-inoperative climb gradient of zero percent, provided that the automatic thrust restoration system will, at a minimum, restore sufficient thrust to maintain the takeoff path engine- inoperative climb gradients specified in FAR Section 25.11 l(c)(3) in the event of an engine failure.
During the thrust reduction, coordinate the pitchover rate and thrust reduction to provide a decrease in pitch consistent with allowing indicated airspeed to decay to no more than 5 knots below the all-engine target climb speed and, in no case to less than V2 for the airplane configuration. For automated throttle systems, acceptable speed tolerances can be found in AC 25-15, Approval of Flight Management Systems in Transport Category Airplanes and maintain the speed and thrust criteria as described in subparagraph 6 a(3) through 6a(5) to 3,000 feet AFE or above, or until the airplane has been fully transitioned to the en route climb configuration (whichever occurs first), then transition to normal en route climb procedures.
The SAT Noise Abatement Policy is that noise sensitive areas exist on all sides of the airport: at pilot’s discretion, climb as quickly and quietly as safely possible on departures and use consideration when flying over populated areas by minimizing flight and high power settings. Engine run-ups are not permitted between 0500-1200Z or 2300 –0600 Central Standard Time (CST). This policy was reprinted from FAA’s Airport /Facility Directory
Ground Run-Up Enclosure (GRE)
The Ground Run-Up Enclosure (GRE) is located on the Airport property near the intersection of Runways 12L/30R and 3/21. This structure allows aircraft to perform maintenance engine checks with minimal disturbance to the nearby communities. This facility can accommodate large air carrier aircraft, up to a B-747. The GRE was completed in May 2002..
There is no cost for use of the facility because it provides an economic resource for the community by allowing aircraft maintenance on a 7 day a week 24 hour a day basis.
Noise test of the GRE reduced a Boeing 727 engine run-up noise by 16.3 dBA at 400 feet, and a 16-db reduction in aircraft noise levels from the use of the facility over open-air engine runs. It maintains less than 1% non usage due to its design and availability.
RESIDENTIAL ACOUSTICAL TREATMENT PROGRAM (ATP)
Background Information
In 2002, the Federal Aviation Administration (FAA) approved a Noise Compatibility Study Update for the San Antonio International Airport that recommended adoption of a Residential Acoustical Treatment Program (ATP) designed to reduce interior aircraft noise in eligible homes located in close proximity to the airport.
Only properties located within FAA approved Noise Exposure Map (NEM) noise contour boundaries are eligible for ATP participation. NEM noise contours are generated by FAA noise modeling software that utilizes actual San Antonio International Airport data (including number of aircraft operations, type of aircraft, times of aircraft operation, arrival and departure headings and aircraft altitudes). Funding for the ATP is provided by FAA Grants (80%) and local airport funds (20%). No City, County or State taxes are used to fund the ATP.
Block Prioritization
Currently underway is the establishment of a block prioritization methodology which will define the “order” for eligible homes to be acoustically treated. Homes located in the highest noise exposure area (75 decibels) will be treated first, followed by homes in lesser noise exposure areas (to 65 decibels). This strategy is currently being reviewed by the FAA and once approval is received, homeowner and contractor outreach can begin.
Acoustical Treatments
By providing acoustical treatments to a home, the ATP can effectively reduce interior noise levels from exterior aircraft by a minimum of 5 decibels, which is equivalent to doubling the distance of the aircraft from the roof of the home. Acoustical treatments may include replacement of existing windows and doors as well as other modifications as may be deemed necessary to achieve the noise level reduction.
ATP Process and Advantages
The ATP is designed to utilize a “single parcel” bidding method, where each home represents an independent design and construction contract. This process is designed to maximize homeowner satisfaction, local contractor participation and quality of work. Advantages to this bidding method include the following:
- Individual Attention to Homeowners
Homeowners receive clear and precise information regarding the program process and timeline and are assigned a Homeowner Agent to assist them throughout the entire process. - Local Contractor Participation
The ATP will soon begin contractor outreach in order to find the best qualified local general contractors to participate in the ATP. Due to its stringent requirements, this qualification process will ensure a high level of construction quality to ATP homes. - Homeowner Selection of Contractors to Bid
Eligible homeowners are able to meet contractors at “General Contractor Interview Night” and select three (3) contractors to bid on their home’s acoustical treatment package. The contractor providing the lowest, responsible bid will be awarded the contract. - Homeowner Product Style and Color Choices
The ability to select from various available treatment products allows the homeowner to maintain an “individual design” for the modification to their home. Involvement in the selection of contractors who may be working in their home also provides a measure of comfort. - Interior Noise Reduction Benefit
An acoustical treatment package is developed for each home and is designed to reduce the interior noise level by a minimum of 5 decibels. In addition to the acoustical benefits, ATP acoustical treatments will provide better thermal efficiency as well as improve home (and neighborhood) aesthetics.
Anticipated ATP Phase 1 Activity
On April 7, 2005 the City of San Antonio authorized the execution of a Professional Services Contract with the firm of THC, Inc., as the Acoustical Treatment Consultant (ATC) to manage the ATP. A 2-year contract was signed in May, 2005, with an option to renew for an additional 2-year term. THC is responsible for the overall execution of the ATP to include homeowner communication, general contractor qualification, design, bidding, product procurement and construction. The budget will allow for acoustical treatment of approximately 224 homes, anticipated to begin in early 2006.
Future Phases
An Environmental Impact Statement is being conducted for San Antonio International Airport under the management of the Federal Aviation Administration. The results of this study, as approved by the FAA, may have an effect on various activities, operations and programs at International Airport, including the Acoustical Treatment Program. Therefore, the ATP may have to be modified to account for any measures accepted and approved by the FAA through the EIS process.
Contact Information
For additional information, contact Mr. Jerry Rankin at the San Antonio International Airport - Noise Mitigation Office at 207-3471.
Newer Quieter Aircraft
Over the years, aircraft have become quieter as national and international regulations have mandated the development of new technologies. SAT has always capitalized on the introduction of quieter aircraft types through local regulations and other methods to attract newer planes to the South Texas Area. Those efforts have come to fruition now that all large aircraft in the U.S. meet the quietest existing noise standard known as Stage 3. Previous Stage 1 and 2 commercial aircraft over 75,000 pounds takeoff weight have been phased out of operation here. Efforts continue to develop quieter technology.
Pilot Awareness Program
This program enhances pilot awareness of noise-sensitive areas and noise abatement procedures by providing information for Jeppesen charts, airline pilot manuals, and fixed based operator information.
The objective of this measure is to maximize the benefits of the noise abatement measures. Most pilots operating at SAT in multi-engine or jet aircraft and many of those operating in single engine aircraft subscribe to a service which provides regular updates to a reference manual on instrument procedures in use at airports. The Jeppesen-Sanderson, Inc produces this type of publication. These types of inserts have been a very successful means of educating pilots on the details of noise abatement procedures at other locations.
All proposed language must be submitted and approved by the FAA for review prior to any publication. The location of, and language contained in, any airport signage must be also be pre-approved by the FAA.
Airport Awareness Zone
The City of San Antonio Development Services and Zoning Department has established an Airport Awareness Zone surrounding both San Antonio International and Stinson Municipal Airports. This boundary requires all development and zoning changes to be reviewed by the Aviation Department to help maintain compatible land uses.
All formal applications for zoning changes have specific language stating that cases within these Airport Awareness Zones are to be reviewed by the Aviation Department and may require additional days for proper review