Paragraph 8 Noise certification reference procedures
(1)
The reference procedure must be calculated under the following atmospheric conditions—
(a)
sea level atmospheric pressure of 1013.25 hPa;
(b)
ambient temperature of 25°C at 1.2m above ground.
(2)
The reference flight procedure must comprise a series of level flights overhead the noise measurement position at a height of 150m (492 ft) and at maximum take-off power.