36_37
I, Doc 8186, Section 7 [38] and FAA Advisory Circular AC 91-53A (Noise Abatement Departure Profile) [39] contain guidance for the development of two different NADPs, each designed to mitigate noise as shown in Figure 14 on the next page. NADP1 procedures are designed for airport closein communities, while NADP2 procedures are for more distant community noise reduction. Examples of both NADP1 and NADP2 procedures can be found in ICAO Doc 8168 Aircraft Operations, Volume 1 Flight Procedures [40].
The close-in procedure (NADP 1) leverages automated engine thrust management. At a specified altitude, thrust is reduced to a lower climb power setting. The distant procedure (NADP 2) leverages flap retraction and takeoff thrust to accelerate and climb quicker, then thrust is reduced [41]. This procedure minimises aircraft noise farther from the airport by permitting the aircraft to climb higher before reducing thrust. Both noise abatement procedures are designed for maximum flexibility and can be customised for individual airports communities.
Figure 13 - John Wayne Airport Noise Abatement Procedures (Source: Orange County Register)