Federal Aviation Administration, DOT Pt. 36, App. F (d) The following atmospheric data, measured immediately before, after, or during each test at the observation points prescribed in section F36.101 of this appendix must be reported: (1) Air temperature and relative humidity. (2) Maximum, minimum, and average wind velocities. (e) Comments on local topography, ground cover, and events that might interfere with sound recordings must be reported. (f) The following airplane information must be reported: (1) Type, model and serial numbers (if any) of airplanes, engines, and propellers. (2) Any modifications or nonstandard equipment likely to affect the noise characteristics of the airplane. (3) Maximum certificated takeoff weights. (4) Airspeed in knots for each overflight of the measuring point. (5) Engine performance in terms of revolutions per minute and other relevant parameters for each overflight. (6) Aircraft height in feet determined by a calibrated altimeter in the aircraft, approved photographic techniques, or approved tracking facilities. (g) Aircraft speed and position and engine performance parameters must be recorded at an approved sampling rate sufficient to ensure compliance with the test procedures and conditions of this appendix. Sec. F36.111 Flight procedures. (a) Tests to demonstrate compliance with the noise level requirements of this appendix must include at least six level flights over the measuring station at a height of 1,000- Section30- and Section10 degrees from the zenith when passing overhead. (b) Each test over flight must be conducted: (1) At not less than the highest power in the normal operating range provided in an Airplane Flight Manual, or in any combination of approved manual material, approved placard, or approved instrument markings; and (2) At stabilized speed with propellers synchronized and with the airplane in cruise configuration, except that if the speed at the power setting prescribed in this paragraph would exceed the maximum speed authorized in level flight, accelerated flight is acceptable. PART C - DATA CORRECTION Sec. F36.201 Correction of data. (a) Noise data obtained when the temperature is outside the range of 68 degrees F. Section9 degrees F., or the relative humidity is below 40 percent, must be corrected to 77 degrees F. and 70 percent relative humidity by a method approved by the FAA. (b) The performance correction prescribed in paragraph (c) of this section must be used. It must be determined by the method described in this appendix, and must be added algebraically to the measured value. It is limited to 5dB(A). (c) The performance correction must be computed by using the following formula: - - R/C - - + 50 - -dB = 60 - 20 log 10 -(11, 430 - D 50 V - - y Where: D50 = Takeoff distance to 50 feet at maximum certificated takeoff weight. R/C = Certificated best rate of climb (fpm). Vy = Speed for best rate of climb in the same units as rate of climb. (d) When takeoff distance to 50- is not listed as approved performance information, the figures of 2000 for single-engine airplanes and 1600- for multi-engine airplanes must be used. (a) The test results must produce an average dB(A) and its 90 percent confidence limits, the noise level being the arithmetic average of the corrected acoustical measurements for all valid test runs over the measuring point. PART D - NOISE LIMITS Sec. F36.301 Aircraft noise limits. (a) Compliance with this section must be shown with noise data measured and corrected as prescribed in Parts B and C of this appendix. (b) For airplanes for which application for a type certificate is made on or after October 10, 1973, the noise level must not exceed 68 dB(A) up to and including aircraft weights of 1,320 pounds (600 kg.). For weights greater than 1,320 pounds up to and including 3,630 811 VerDate Sep<11>2014 12:50 Apr 30, 2019 Jkt 247046 PO 00000 Frm 00821 Fmt 8010 Sfmt 8002 Y:\SGML\247046.XXX 247046 EC28SE91.113 spaschal on DSK3GDR082PROD with CFR Sec. F36.203 Validity of results. (b) The samples must be large enough to establish statistically a 90 pecent confidence limit not to exceed Section1.5 dB(A). No test result may be omitted from the averaging process, unless omission is approved by the FAA.