PART 13 -- Noise test code

• Regulation (EU) 2020/1058 found in: Unmanned Aircraft Systems (No 2019/947 and 2019/945) Part-UAS (Jul 2024)

PART 13 — Noise test code Regulation (EU) 2020/1058 This Part lays down the methods of measurement of airborne noise that shall be used for the determination of the measured A-weighted sound power levels of UA classes 1, 2, 3, 5 and 6. It lays down the basic noise emission standard and detailed test code for measuring the sound pressure level on a measurement surface enveloping the source and for calculating the sound power level produced by the source. 1. BASIC NOISE EMISSION STANDARD For the determination of the A-weighted sound power level *LWA* of UA, the basic noise emission standards EN ISO 3744:2010 will be used subject to the following supplements: 2. INSTALLATION AND MOUNTING CONDITIONS *Test area:* The UA will be maintained above one reflecting (acoustically hard) plane. The UA shall be located at a sufficient distance from any reflecting wall or ceiling or any reflecting object so that the requirements given in Annex A of EN ISO 3744:2010 are satisfied on the measurement surface. *Sound measurement surface and microphone array:* The UA will be completely enclosed in a hemispherical measurement surface as per § 7.2.3 of EN ISO 3744:2010. The number and position of the microphones is defined by Annex F of EN ISO 3744:2010. The measurement surface shall have its origin at the point O lying in the ground plane directly below the UA. 3. OPERATING CONDITIONS DURING TEST The noise tests shall be carried out with the UA’s rotors operating at a speed corresponding to the hovering of the UA under MTOM. If the UA is placed on the market with accessories that can be fitted to it, it will be tested with and without these accessories in all possible UA configurations. 4. CALCULATION OF SURFACE TIME-AVERAGED SOUND PRESSURE LEVEL The A-weighted surface time-averaged sound pressure level shall be determined at least three times for each UA configuration. If at least two of the determined values do not differ by more than 1 dB, further measurements will not be necessary; otherwise the measurements shall be continued until two values differing by no more than 1 dB are obtained. The surface time‑averaged sound pressure level to be used for calculating the sound power level of a UA configuration is the arithmetic mean of the two highest values that do not differ by more than 1 dB. 5. INFORMATION TO BE REPORTED The report shall contain the technical data necessary to identify the source under test as well as the noise test code and the acoustical data. The A-weighted sound power level value to be reported is the highest value of the different UA configurations tested rounded to the nearest whole number (less than 0,5 use the lower number; greater than or equal to 0,5 use the higher number).