Measurement and characterization of helicopter noise in steady-state and maneuvering flight

Fredric H. Schmitz, Eric Greenwood, Richard D. Sickenberger, Gaurav Gopalan, Ben Wel C. Sim, David Conner, Ernesto Moralez, William A. Decker

Research output: Contribution to journalConference article

12 Citations (Scopus)

Abstract

A special acoustic flight test program was performed on the Bell 206B helicopter outfitted with an in-flight microphone boom/array attached to the helicopter while simultaneous acoustic measurements were made using a linear ground array of microphones arranged to be perpendicular to the flight path. Air and ground noise measurements were made in steady-state longitudinal and steady turning flight, and during selected dynamic maneuvers. Special instrumentation, including direct measurement of the helicopter's longitudinal tip-path-plane (TPP) angle, Differential Global Positioning System (DGPS) and Inertial Navigation Unit (INU) measurements, and a pursuit guidance display were used to measure important noise controlling parameters and to make the task of flying precise operating conditions and flight track easier for the pilot. Special care was also made to test only in very low winds. The resulting acoustic data is of relatively high quality and shows the value of carefully monitoring and controlling the helicopter's performance state. This paper has shown experimentally, that microphones close to the helicopter can be used to estimate the specific noise sources that radiate to the far field - if the microphones are positioned correctly relative to the noise source. Directivity patterns for steady, turning flight were also developed, for the first time, and connected to the turning performance of the helicopter. Some of the acoustic benefits of combining normally separated flight segments (i.e. an accelerated segment and a descending segment) were also demonstrated.

Original languageEnglish (US)
Pages (from-to)28-44
Number of pages17
JournalAnnual Forum Proceedings - AHS International
Volume1
StatePublished - Aug 20 2007
EventAmerican Helicopter Society International 63rd Annual Forum - Riding the Wave of New Vertical Flight Technology - Virginia Beach, VA, United States
Duration: May 1 2007May 3 2007

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Helicopters
Microphones
Acoustics
Flight paths
Global positioning system
Navigation
Display devices
Monitoring
Air

All Science Journal Classification (ASJC) codes

  • Engineering(all)

Cite this

Schmitz, F. H., Greenwood, E., Sickenberger, R. D., Gopalan, G., Sim, B. W. C., Conner, D., ... Decker, W. A. (2007). Measurement and characterization of helicopter noise in steady-state and maneuvering flight. Annual Forum Proceedings - AHS International, 1, 28-44.
Schmitz, Fredric H. ; Greenwood, Eric ; Sickenberger, Richard D. ; Gopalan, Gaurav ; Sim, Ben Wel C. ; Conner, David ; Moralez, Ernesto ; Decker, William A. / Measurement and characterization of helicopter noise in steady-state and maneuvering flight. In: Annual Forum Proceedings - AHS International. 2007 ; Vol. 1. pp. 28-44.
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Schmitz, FH, Greenwood, E, Sickenberger, RD, Gopalan, G, Sim, BWC, Conner, D, Moralez, E & Decker, WA 2007, 'Measurement and characterization of helicopter noise in steady-state and maneuvering flight', Annual Forum Proceedings - AHS International, vol. 1, pp. 28-44.

Measurement and characterization of helicopter noise in steady-state and maneuvering flight. / Schmitz, Fredric H.; Greenwood, Eric; Sickenberger, Richard D.; Gopalan, Gaurav; Sim, Ben Wel C.; Conner, David; Moralez, Ernesto; Decker, William A.

In: Annual Forum Proceedings - AHS International, Vol. 1, 20.08.2007, p. 28-44.

Research output: Contribution to journalConference article

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AU - Greenwood, Eric

AU - Sickenberger, Richard D.

AU - Gopalan, Gaurav

AU - Sim, Ben Wel C.

AU - Conner, David

AU - Moralez, Ernesto

AU - Decker, William A.

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