Options for Airport Approach Noise Control: Flight Procedures,Aircraft Certification,and Airport Restrictions

The use of larger aircraft and high-bypass engines has made the approach noise at airports more critical, but the methods used to control it rely on rather tenuous relationships between aircraft noise certification and the noise experienced by the communities around airports. Also, the options for alleviating approach noise are perceived to be fewer than for the takeoff case. The effect of a variety of possible approach flight procedures is explored. All of these procedures terminate in a conventional 3-degree final glide path, on the maximum noise levels under the flight path. In comparison, the effect of varying the glideslope angle on noise at the approach certification point is reported. It is concluded that the most promising procedures for alleviating noise in the areas some distance from an airport are the Continuous Descent and the Decelerating approaches. The current use of these techniques is limited by the incompatibility with air traffic control procedures. The more severe noise levels closer to the runway threshold could be significantly alleviated by the use of steeper approaches without serious consequences for the aircraft operators. It is argued that, if the airports are to be discouraged from their current practice of unilaterally imposing environmentally induced constraints on operations, a modified noise certification procedure is needed that better relates to the actual behavior of aircraft and the location of the disturbance. Options for this are considered, and it is concluded that only a full systems analysis—including airlines, air traffic control, airports, and the regulators—can synthesize an effective noise control methodology.