Paragraph 2 Test procedures

(1)

All flight test procedures used in demonstrating compliance with the noise certification requirements must be consistent with the airworthiness certification basis of the aeroplane.

(2)

The tests must be carried out under the following atmospheric conditions—

(a)

no precipitation;

(b)

ambient temperature not above 35°C and not below 2°C at 1.2m above ground;

(c)

relative humidity not higher than 95 per cent and not below 20 per cent at 1.2m above the ground;

(d)

on a diagram of relative humidity plotted against temperature, combinations of relative humidity and temperature which fall below a straight line between (60 per cent, 2°C) and (20 per cent, 35°C) are unacceptable;

(e)

reported wind speed, when measured at 1.2m above the ground, must not exceed 19 km/hr (10 knots) and cross wind component must not exceed 9 km/hr (5 knots);

(f)

no temperature inversion or anomalous weather conditions that would significantly affect the noise levels of the microlight aeroplane observed at the specified measurement position.

(3)

Flights must be made in equal numbers with tail and head wind components.

(4)

Subject to subparagraph (5) the microlight aeroplane must pass overhead the noise measurement position within ±10° of the vertical at a height of 150 (+10/-70) m (490 (+33/-230) ft).

(5)

The CAA may, having regard to the poor definition, in some circumstances, of the noise field shape for microlight aeroplanes at 150m determine that the test be undertaken at a height of 100 (+60/-20) m (328 (+197/-60) ft).

(6)

Overflights must be performed at stabilised speed in the cruise configuration, except that where the speed at take-off power would exceed the maximum speed authorised in level flight, climbing flight is acceptable.

(7)

The maximum static propeller speed must be measured using a device accurate to within ±1 per cent.

(8)

When requested in advance by the CAA, tape recordings of the noise tests must be provided. In such cases the instrumentation standards and procedures must be those described in paragraph 4.

Notes on the whole SI

Textual amendments

F1: Order title amended (31.12.2020) by The Aviation Noise (Amendment) (EU Exit) Regulations 2019 (S.I. 2019/643), reg. 3(2); 2020 c. 1, Sch. 5 para. 1(1)