MEASURED NOISE REDUCTIONS RESULTING FROM MODIFIED APPROACH PROCEDURES FOR BUSINESS JET AIRCRAFT

Five business jet airplanes were flown to determine the noise reductions that result from the use of modified approach procedures. The airplanes tested were a Gulfstream 2, JetStar, Hawker Siddeley 125-400, Sabreliner-60 and LearJet-24. Noise measurements were made 3, 5, and 7 nautical miles from the touchdown point. In addition to a standard 3 deg glide slope approach, a 4 deg glide slope approach, a 3 deg glide slope approach in a low-drag configuration, and a two-segment approach were flown. It was found that the 4 deg approach was about 4 EPNdB quieter than the standard 3 deg approach. Noise reductions for the low-drag 3 deg approach varied widely among the airplanes tested, with an average of 8.5 EPNdB on a fleet-weighted basis. The two-segment approach resulted in noise reductions of 7 to 8 EPNdB at 3 and 5 nautical miles from touchdown, but only 3 EPNdB at 7 nautical miles from touchdown when the airplanes were still in level flight prior to glide slope intercept. Pilot ratings showed progressively increasing workload for the 4 deg, low-drag 3 deg, and two-segment approaches. (Author)

  • Corporate Authors:

    Edwards Flight Research Center

    National Aeronautics and Space Administration
    Edwards, CA  USA  93523
  • Authors:
    • Burcham, FWJ
    • Putnam, T W
    • Lasagna, P L
    • Parish, O O
  • Publication Date: 1975-11

Media Info

  • Pagination: 31 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00146733
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: NASA-TM-X-56037
  • Files: TRIS
  • Created Date: Feb 16 1977 12:00AM