Operational techniques for reducing approach noise from business jet aircraft were evaluated in flight by measuring the noise generated by five such aircraft during modified approaches. Approaches with 4° glide slopes were approximately 4.0 EPNdB quieter than approaches with standard 3° glide slopes. Noise reductions for low-drag 3° approaches varied widely among the airplanes tested; the fleet-weighted reduction was 8.5 EPNdB. Two-segment approaches resulted in noise reductions of 7.0 EPNdB to 8.5 EPNdB 3 nautical miles and 5 nautical miles from touchdown. Pilot workload increased progressively for the 4°, low-drag 3°, and two-segment approach.
Subscribers can view annotate, and download all of SAE's content. Learn More »