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Segmentwise Measurement of Helicopter Approach Noise with a Reduced Microphone Setup

Olsman, W.F.J. and Schuchardt, Bianca I. (2015) Segmentwise Measurement of Helicopter Approach Noise with a Reduced Microphone Setup. Journal of the American Helicopter Society, 60 (4), pp. 1-18. American Helicopter Society. DOI: 10.4050/JAHS.60.042005 ISSN 0002-8711

Full text not available from this repository.

Official URL: http://www.ingentaconnect.com/content/ahs/jahs/2015/00000060/00000004;jsessionid=1viyc73qcjned.alice

Abstract

To measure the noise footprint of a helicopter approach procedure, microphones are usually distributed over a large area. In this paper, however, a method is utilized where the measurement of the noise footprint is conducted in parts by distributing the microphones over a limited area and executing the same approach procedure, while the position of the landing point is shifted. The flight tests are conducted with the EC135-ACT/FHS helicopter. Guidance to the pilots is provided by use of a “tunnel-in-the-sky” head down pilot display. Since the same flight procedure is executed multiple times, it is possible to conduct a statistical analysis on the accuracy and reproducibility of the approach procedure in terms of position, velocity, and generated noise. This statistical analysis shows that the geometric accuracy is on the order of 6 m in the horizontal plane and 12 m in the vertical plane. The variations in the measured sound exposure level from one approach to another are on the order of 3–7.5 dB(A). The approach procedure is also executed with excessive cyclic pilot control inputs to identify an upper limit of the extra noise generated by unsteady flight. However, these approaches are indistinguishable, in terms of the sound exposure level or sound pressure level, from the approaches with normal pilot control inputs.

Item URL in elib:https://elib.dlr.de/98261/
Document Type:Article
Title:Segmentwise Measurement of Helicopter Approach Noise with a Reduced Microphone Setup
Authors:
AuthorsInstitution or Email of AuthorsAuthors ORCID iD
Olsman, W.F.J.jurrien.olsman (at) dlr.deUNSPECIFIED
Schuchardt, Bianca I.bianca.schuchardt (at) dlr.deUNSPECIFIED
Date:27 August 2015
Journal or Publication Title:Journal of the American Helicopter Society
Refereed publication:Yes
Open Access:No
Gold Open Access:No
In SCOPUS:Yes
In ISI Web of Science:Yes
Volume:60
DOI :10.4050/JAHS.60.042005
Page Range:pp. 1-18
Publisher:American Helicopter Society
ISSN:0002-8711
Status:Published
Keywords:Helicpter approach, noise footprint measurement
HGF - Research field:Aeronautics, Space and Transport
HGF - Program:Aeronautics
HGF - Program Themes:rotorcraft
DLR - Research area:Aeronautics
DLR - Program:L RR - Rotorcraft Research
DLR - Research theme (Project):L - The Quiet und Comfortable Rotorcraft
Location: Braunschweig
Institutes and Institutions:Institute of Aerodynamics and Flow Technology > Helicopters
Institute of Flight Systems > Rotorcraft
Deposited By: Olsman, WFJ
Deposited On:24 Sep 2015 08:46
Last Modified:08 Mar 2018 18:45

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