NOISE CONTROL PROCEDURES
ARIZONA MODEL AVIATORS
Superstition Air Park
Noise control procedures shall be in effect at all times at Superstition Air Park, the model aircraft field owned and maintained by Arizona Model Aviators, (hereinafter called AMA). The purpose of these procedures shall be to limit noise created by model aircraft operations at the field, thereby preventing disturbance to neighboring property that could lead to loss of the current facility. Accordingly, the maximum permissible sound level emanating from any model aircraft operating at Superstition Air Park shall be 103 dB for all glow powered aircraft, and 100 dB for all gasoline powered aircraft. Turbine aircraft are exempt. Noise levels shall be measured in accordance with the detailed procedures contained herein. Exceptions for contests and events shall be at the discretion of the Executive Board of the AMA. A copy of these procedures shall be displayed at the field, maintained on the AMA web site, and provided to all pilots participating in contests and events at the field.
2.0 Noise Committee
A Noise Committee shall be formed consisting of current AMA members. This Committee shall be empowered to enforce AMA’s noise control procedures and shall be responsible to propose new or revised procedures. The president of the AMA shall appoint a Chairman of the Noise Committee, who shall in turn assign additional members as necessary. A published list of Noise Committee members shall be posted at the field and on the AMA web site. The AMA shall procure and maintain sound meters, and furnish one to each member of the Noise Committee. Each Noise Committee member shall be trained in proper measurement of sound levels per the procedures herein.
3.0 General Flying
All pilots, whether members of AMA or not, shall comply with these procedures when flying at Superstition Airpark. Noise control shall be in effect during normal and summertime flying hours. Any member of the AMA Noise committee shall be authorized to spot check noise levels from aircraft suspected of exceeding the limit. Aircraft violating the limit shall not be allowed to fly until the situation is corrected. If another member of the noise committee is present, that member may take a second reading with an alternate sound meter and the lower of the two readings used to determine compliance. Pilots who refuse to comply with the noise control procedures shall be asked to leave the field, and shall be reported to the president of the AMA.
4.0 Contests and Events
The AMA’s noise control procedures shall be strictly and uniformly enforced for all contests and events held at Superstition Airpark. Deviations to the noise control procedures may be proposed to the AMA Executive Board by Contest Directors (CD) for consideration and approval if deemed necessary and not harmful to the AMA. A summery of The Noise Control Procedures should be attached to all flyers for events so that prospective pilots will know what to expect in advance. A copy of the Noise Control Procedures shall be provided with each registration packet. Each registration form shall contain a statement, to be signed by the registrant, indicating that the Noise Controls Procedures have been read and agreed to.
The CD shall be responsible to coordinate with The Noise Control Committee members to be present during all flying periods at contests and events. However, The Noise Control Committee may at any time re-test at their discretion. If any modifications are made that will affect noise levels, another measurement shall be required prior to flying. At the discretion of The Noise Committee, noise measurements shall not be required when aircraft size and configuration are such that noise will obviously be within limits.
Pilots whose aircraft exceed the allowable limit may appeal the reading and obtain a second measurement from another Noise Committee member using a different meter. Compliance shall be based on the lower of the two measurements. If a satisfactory reading cannot be obtained, pilots may alter aircraft configuration and settings in an attempt to generate less noise and then request another measurement.
In the case of a dispute, the CD and two Noise Committee members shall vote on whether an aircraft in question meets the allowable limit, with a simple majority deciding the issue.
Pilots who refuse to comply with the Noise Control Procedures or Noise Committee/CD decisions shall not be allowed to fly. Registration fees shall not be refunded to pilots restricted from flying because they can not or will not lower their aircraft noise levels to the allowable limit.
5.0 Noise Measurement Procedures
The detailed Noise Measurement Procedures contained in this section are adapted from the Academy of Model Aeronautics’ “Sound Addendum”.
a) A trained member of the AMA Noise Committee shall make all sound measurements.
b) Sound meters shall be Radio Shack Model 33-2055 Digital or equivalent.
c) Sound meters shall be set to “A” weighting and “Slow” response.
d) Sound measurements shall be taken using the relative distances and orientations shown in Figure 1. Unless otherwise specified for a contest or event, distance “a” shall be 3.0 meters (118 inches). For convenience the proper positions have been stenciled on the field surface in each flight box, and should be used if possible.
e) The sound meter microphone shall be placed at a distance of 12 inches above the field surface. The axis of the meter shall be parallel to the ground and at an angle of 70 degrees from the axis of the aircraft wing. The AMA has fabricated holding fixtures for this purpose.
f) The measurement shall be taken from the side of the aircraft where the exhaust exits. If the exhaust exits at the centerline, the measurement shall be taken on the right side of the aircraft.
g) Pilots and assistants shall position themselves and field equipment as far as possible from the engine and sound meter microphone so as not to obstruct the sound path or absorb/reflect sound energy.
h) The person operating the sound meter shall stay well behind it to prevent absorption/reflection of sound.
i) When all equipment and personnel are properly arranged, the throttle shall be advanced to wide open for a minimum of 5 seconds or until the engine reaches its maximum/peak as determined by the checker, during which time the measurement shall be taken.
j) The person operating the radio transmitter shall clearly demonstrate to the Noise Committee member that full throttle is being commanded.
k) dB check. If a plane meets requirements set forth by Arizona Model Aviators Association dB levels it will be logged in the Log Book by Plane description, engine, prop, muffler system and owner, for ARIZONA MODEL AVIATORS ASSOCIATION information. This information will be made available to Parks if necessary (without the owner’s name as per privacy issue). If plane passes dB check, the plane will be given the OK to fly, as it has met ARIZONA MODEL AVIATORS ASSOCIATION guide lines and stated so by Date and dB reading in the sound Log Book.
l) If the plane fails ARIZONA MODEL AVIATORS ASSOCIATION sound requirements:
• The pilot or owner can make any necessary changes to the aircraft, not limited to prop changes, muffler changes, or limiting throttle settings to achieve required sound levels set forth by ARIZONA MODEL AVIATORS ASSOCIATION. The plane cannot fly until repair has been made
• When the owner/pilot feels his aircraft is ready for re-test, the plane will be re-tested. If the plane fails again, the owner/pilot will have to re-test until the plane meets the sound requirements. The plane cannot fly until the requirements are met.
m) Any sound complaint for test of any air craft must be put in writing with complainant’s name, date, type of aircraft or pilot or owner’s name. No test will be done without a written complaint for sound test. This is for members or non members alike. The owner/pilot of suspect plane will be given notice of re-test and must make the plane available for re-test. If the owner/pilot refuses to comply, the plane will not be allowed to fly until the re-test is complete and it is confirmed that the plane meets ARIZONA MODEL AVIATORS ASSOCIATION sound requirements. Sound complaint will be logged in the Log Book to show aircraft is in compliance.
Noise Test Geometry