Noise reductions achieved on a 720-023B aircraft using a two-segment approach

A flight investigation to determine the operational feasibility of two-segment approaches as a means for reducing airport community noise has been conducted. The effective perceived noise level (EPNL) associated with these approach profiles, using a 720-023B jet aircraft, has been obtained. The tests were designed to determine an operationally optimum approach profile and to quantify the reduction in noise level at predetermined locations on the ground beneath the flight track. The acoustic aspects of the test program are examined. An analysis of the optimum and reference profiles was made using a group of pilots. Information was also obtained on the types of pilot operational procedures used for the optimum profile.