This case study looks at the implementation of a noise abatement operational procedure (NADP2) provide noise relief to communities around Schiphol from departing aircraft. At the same time, it was anticipated that this change would deliver fuel savings for airlines.
To provide noise relief to communities around airports from departing aircraft.
Two specific noise abatement departure procedures (NADP’s) were developed to mitigate air traffic noise. The NADP describes the procedure in which the aircraft transits from the high take-off power having extended flaps and slats settings towards a climb phase using climb power and all flaps and slats retracted. The NADP1 departure procedure effectively confines the noise impact within a small area around the airport. NADP2 has a distant cross-over point to become quieter than NADP1 and is most effective to reduce fuel consumption. The main difference is that the altitude at which the aircraft starts accelerating is reduced from 3000 ft (NADP1) to 1500 ft (NADP2).
Figure 3. Comparison of the ground speed and the lateral noise exposure between NADP1 and NADP2. The NADP2 departure procedure reduces noise exposure due to a shorter fly over event and a smaller lateral area of exposure than NADP1.
The noise exposure is shorter due to a higher ground speed when NADP2 is used compared to NADP1. For the NADP2 departure procedure, the flight altitude is lower, which results in a reduction of the lateral noise exposure.
Figure 4. Illustration of the climb heights between NADP1 and NADP2. The NADP2 procedure starts with a steeper climb where the acceleration required for flaps and slats retraction starts at 1500 ft.