Showing papers on "Aircraft noise published in 1999"
01 Jan 1999
TL;DR: In this paper, the authors used a 3-engine nacelle model with a high frequency wideband point source inside the nacelles of the center engine and one of the side engines in order to simulate broadband engine noise.
Abstract: Noise shielding benefits associated with an advanced unconventional subsonic transport concept, the Blended-Wing-Body, were studied using a 4- percent scale, 3-engine nacelle model. The study was conducted in the Anechoic Noise Research Facility at NASA Langley Research Center. A high- frequency, wideband point source was placed inside the nacelles of the center engine and one of the side engines in order to simulate broadband engine noise. The sound field of the model was measured with a rotating microphone array that was moved to various stations along the model axis and with a fixed array of microphones that was erected behind the model. Ten rotating microphones were traversed a total of 22 degrees in 2-degree increments. Seven fixed microphones covered an arc that extended from a point in the exhaust exit plane of the center engine (and directly below its centerline) to a point 30 degrees above the jet centerline. While no attempt was made to simulate the noise emission characteristics of an aircraft engine, the model source was intended to radiate sound in a frequency range encompassing 1, 2, and 3 times the blade passage of a typical full-scale engine. In this study, the Blended-Wing-Body model was found to provide significant shielding of inlet noise. In particular, noise radiated downward into the forward sector was reduced by 20 to 25 dB overall in the full-scale frequencies from 2000 to 4000 Hz, decreasing to 10 dB or less at the lower frequencies. Also, it was observed that noise associated with the exhaust radiates into the sector directly below the model downstream to reduce shielding efficiency.
52 citations
TL;DR: Results showed a significant decrease of total quality of life 18 month after aircraft noise exposure as well as a motivational deficits operationalized by fewer attempts to solve insoluble puzzles in the new airport area, in accord with reports of impaired psychological health after noise exposure.
Abstract: Psychological effects of aircraft noise exposure on children have only recently been addressed in the literature. The current study took advantage of a natural experiment by the opening of a new airport, exposing formerly nonexposed children to low aircraft noise. In this prospective longitudinal investigation, which employed nonexposed control groups, effects of aircraft noise prior to inauguration of the new airport, as well as effects of chronic noise and its reduction at the old airport, were studied in children aged 9 to 13 years. The psychological health of children was investigated with a standarized quality of life scale as well as with a motivational measure. In addition, a self‐report noise annoyance scale was used. In the 393 children studied at the new airport over three time points, results showed a significant decrease of total quality of life 18 months after aircraft noise exposure, as well as a motivational deficit in the new airport area. In the old airport, parallel impairments were present before the airport relocation but subsided thereafter. These findings are in accord with reports of impaired psychological health after noise exposure and indicate the relevance of monitoring psychological parameters as a function of environmental stressors among children.
45 citations
TL;DR: In this article, the authors investigated the importance of perceived risk to environmental quality and dispositions to be generally annoyed or sensitive to noise in predicting disturbance from aviation noise by distributing a mail-back questionnaire to 901 residents in neighborhoods bordering a small developing airport.
Abstract: The comparative importance of perceived risk to environmental quality and dispositions to be generally annoyed or sensitive to noise in predicting disturbance from aviation noise was investigated by distributing a mail-back questionnaire to 901 residents in neighborhoods bordering a small developing airport. An Environmental Noise Risk scale, developed by the authors, assessed how individuals appraise the trade-off between economic benefits from airport development and adverse environmental effects. Stepwise multiple regression analysis (N = 358) showed that as hypothesized, disturbance was predicted by assessment of environmental noise risk (β = .60, p < .0001) but not by general annoyance or noise sensitivity. Those disturbed by noise were also more discriminating in their evaluation of other less salient attributes of neighborhoods. Environmental noise risk is discussed as a construct that can contribute to understanding how people evaluate the consequences of a developing noise source.
34 citations
01 Sep 1999
TL;DR: In this paper, the implications of new environmental policies in conjunction with airline deregulation and change in the airport infrastructure are examined, focusing on the specifics of Sydney Kingsford Smith Airport, and broader policy issues likely to be relevant for other major airports around the world are discussed.
Abstract: This paper provides an empirical examination of the implications of new environmental policies in conjunction with airline deregulation and change in the airport infrastructure. This paper discusses principles and policy analyses. By focusing on the specifics of Sydney Kingsford Smith Airport, broader policy issues likely to be relevant for other major airports around the world are discussed.
29 citations
01 Sep 1999
TL;DR: The FAA Integrated Noise Model (INM) 7.0 as discussed by the authors was developed with support from the ATAC Corporation and the Department of Transportation Volpe National Transportation Systems Center (NTSC).
Abstract: The Federal Aviation Administration, Office of Environment and Energy, Noise Division (FAA, AEE-100) has developed Version 7.0 of the Integrated Noise Model (INM) with support from the ATAC Corporation and the Department of Transportation Volpe National Transportation Systems Center. The FAA Integrated Noise Model is widely used by the civilian aviation community for evaluating aircraft noise impacts in the vicinity of airports. The model is typically used in the U.S. for FAR Part 150 noise compatibility planning, FAR Part 161 approval of airport noise restrictions, and for environmental assessments and environmental impact statements under the current version of FAA Order 1050.1E. New features in INM 7.0 include: lateral attenuation calculations based on SAE-AIR-5662; flight path segmentation, flight procedure step types, bank angle calculations, and thrust reverser implementation based on ECAC Doc 29; helicopter modeling methods based on Version 2.2 of FAA’s Heliport Noise Model (HNM); an HNM study import function; a scenario annualization function allowing operations to be adjusted after performing a run; a multi-threaded run mode; fixed-spacing contour grid functionality; increased differentiation between different type of aircraft (civil, military, and helicopter); the ability to input location values in lat/long or X/Y; and many extended database fields. INM Version 7.0 software runs on PCs using a minimum hardware configuration of a Pentium III processor, Microsoft Windows 2000 or XP operating systems, 1.0-Gb RAM, mouse input device, hard disk drive, and CD-ROM drive.
20 citations
Journal Article•
TL;DR: The authors suggests changes should be made to the regulatory framework governing the control of aircraft noise through reestablishment of the Office for Noise Abatement and Control within the Environmental Protection Agency, additional funds for noise mitigation projects, as well as a shift in the liability structure for noise violations.
Abstract: Airport noise pollution is a widespread and growing problem in the United States. Traditionally the regulation of airport noise was left to state and local regulatory efforts as well as judicial actions brought under nuisance and inverse condemnation theories of liability. With the enactment of several pieces of federal legislation beginning in the 1970s, however, Congress has clarified its intent to preempt local control of airport noise. Local governments and airport proprietors have to comply with a complicated scheme of federal regulation and rely on insufficient funds to fully address the airport noise problem in their communities. This Comment suggests changes should be made to the regulatory framework governing the control of aircraft noise through reestablishment of the Office for Noise Abatement and Control within the Environmental Protection Agency, additional funds for noise mitigation projects, and research on the effects of aircraft noise, as well as a shift in the liability structure for noise violations.
16 citations
Journal Article•
TL;DR: The background to noise management at Heathrow is described in some detail and a general conclusion that taking non-acoustic factors into account in addition to physical noise levels alone has been of considerable benefit over the years is drawn.
Abstract: Non-acoustic factors in environmental noise can be broadly defined as all those factors other than noise level alone which contribute to noise annoyance and similar effects. Noise levels such as LAeq provide a good indication of the amount of physical noise present, and changes in physical noise level can be expected to correlate with changes in resident's perception, at least to some degree. On the other hand, a flexible approach to noise management based on wide consultation and communication can be extremely important. At Heathrow Airport over the last 20 to 30 years, overall aircraft noise levels have reduced because of the phasing out of the older noisier Chapter 2 aircraft types, but there are also other strategies in place which are clearly regarded as being effective both by airport management and by local community representatives and which are not as easily quantified in terms of noise level alone. This paper describes the background to noise management at Heathrow in some detail and draws a general conclusion that taking non-acoustic factors into account in addition to physical noise levels alone has been of considerable benefit over the years.
12 citations
TL;DR: In this article, the effects of the noise level and type of noise source on activity disturbance were investigated by a simulated-environment study and the results indicated that the correlation coefficients between the activity disturbance and noise level were high (r=0·951 and 0·970).
11 citations
10 May 1999
TL;DR: In this article, a flight test is described in which an active structural/acoustic control system reduces turboprop induced interior noise on a Raytheon Aircraft Company 1900D airliner.
Abstract: A flight test is described in which an active structural/acoustic control system reduces turboprop induced interior noise on a Raytheon Aircraft Company 1900D airliner. Control inputs to 21 inertial force actuators were computed adaptively using a tansform domain version of the multichannel filtered-X LMS algorithm to minimize the mean square response of 32 microphones. A combinatorial search algorithm was employed to optimize placement of the force actuators on the aircraft frame. Both single frequency and multi-frequency results are presented. Reductions of up to 15 dB were obtained at the blade passage frequency (BPF) during single frequency control tests. Simultaneous reductions of the BPF and next 2 harmonics of 10 dB, 2.5 dB and 3.0 dB, are obtained in a multi-frequency test.
11 citations
01 Jul 1999
TL;DR: This study found that visitors tend to be less annoyed by aircraft noise if they remember learning that they could hear or see aircraft while in the Park, and shows the importance of informing visitors about possible aircraft overflights - i.e., managing visitor expectations.
Abstract: : This study was initiated as part of the cooperative US Air Force/National Park Service efforts to understand and effectively manage the potential adverse effects military air crew training can have on the National Parks. Through simultaneous sound data acquisition and Park user interviews, data were collected that provided a basis for determining how military jet overflights can affect visitor experience at a site in White Sands National Monument, New Mexico. Several useful findings resulted from the analysis. First, visitors can distinguish between the concepts of "annoyance" and "interference" produced by aircraft sound. Annoyance is an emotional reaction, while interference is more of an objective judgment. Visitors can find that the sound of aircraft interferes with the natural soundscape, but are not necessarily annoyed. Visitors believe annoyance results if the interference is often or severe enough. Second, visitors tend to be less annoyed by aircraft noise if they remember learning that they could hear or see aircraft while in the Park. This finding shows the importance of informing visitors about possible aircraft overflights - i.e., managing visitor expectations. Finally, aircraft noise is likely to produce less annoyance if aircraft fly over in close succession, rather than widely spaced, one at a time.
10 citations
01 May 1999
TL;DR: In this article, the authors summarized on-going modal testing activities at the NASA Langley Research Center for two aircraft fuselage structures: a generic "aluminum testbed cylinder" (ATC) and a Beechcraft Starship fuselage (BSF).
Abstract: This paper summarizes on-going modal testing activities at the NASA Langley Research Center for two aircraft fuselage structures: a generic "aluminum testbed cylinder" (ATC) and a Beechcraft Starship fuselage (BSF). Subsequent acoustic tests will measure the interior noise field created by exterior mechanical and acoustic sources. These test results will provide validation databases for interior noise prediction codes on realistic aircraft fuselage structures. The ATC is a 12-ft-long, all-aluminum, scale model assembly. The BSF is a 40-ft-long, all-composite, complete aircraft fuselage. To date, two of seven test configurations of the ATC and all three test configurations of the BSF have been completed. The paper briefly describes the various test configurations, testing procedure, and typical results for frequencies up to 250 Hz.
Journal Article•
TL;DR: The importance of formal consideration of response bias in assessments of the adequacy of regulatory enforcement levels is addressed and regulatory limitation of noise levels to certain values of favored noise metrics may provide the appearance of a solution to problems of community reaction to aircraft noise.
Abstract: A fundamental goal of aircraft noise regulation is control of the prevalence of noise-induced annoyance in airport communities. A common regulatory strategy is to identify values of long-term, time-weighted average aircraft noise exposure that may not be exceeded in the vicinity of airports without certain consequences. Noise exposure per se is neither the sole cause nor a perfect predictor of the annoyance of aircraft noise, however. Regulatory limitation of noise levels to certain values of favored noise metrics may therefore provide the appearance, rather than the substance, of a solution to problems of community reaction to aircraft noise. Response bias, as identified by Green and Fidell (1991), is a factor that exerts about as much influence on the observed prevalence of annoyance in communities as cumulative noise exposure. The importance of formal consideration of response bias in assessments of the adequacy of regulatory enforcement levels is addressed.
TL;DR: In this paper, a quasi-experimental field study was conducted to investigate aircraft-noise-induced annoyance in outdoor recreational areas, which was conducted near Fornebu Airport in Oslo, Norway.
Abstract: A quasi-experimental field study was conducted to investigate aircraft-noise-induced annoyance in outdoor recreational areas. This study, which is part of a larger project that also includes a social survey, was conducted near Fornebu Airport in Oslo, Norway. The aim of the study was to investigate annoyance due to aircraft noise in an outdoor setting under partially controlled conditions. Results are presented for exposure--annoyance relationships, acceptability judgments, and relationhips between immediate annoyance responses to overflights and total annoyance over a longer period.
TL;DR: The principal aircraft and engine manufactures in Europe are facing increasing pressure to reduce aircraft noise levels as discussed by the authors, both from the community expectations of improved quality of life and from the need to compensate for the expected growth in air traffic.
02 Feb 1999
TL;DR: Aeroacoustic research has benefited from the development of advanced techniques for the study of fluid mechanically generated noise New instrumentation; methodologies, information technologies, and facilities have evolved to help researchers investigate the complexities of aircraft and automobile noise.
Abstract: Aeroacoustic research has benefited from the development of advanced techniques for the study of fluid mechanically generated noise New instrumentation; methodologies, information technologies, and facilities have evolved to help researchers investigate the complexities of aircraft and automobile noise. In this paper, research techniques are reviewed with emphasis on the subject closest to the author s experience: aircraft propulsion and airframe noise in simulated flight. A new technology developed for the study of aircraft airframe noise is described as a potential tool for the study of automobile noise. The important role of information technology in aeroacoustic research is discussed.
01 Dec 1999
TL;DR: In this article, a pilot simulation study was conducted for the purpose of predicting the noise reduction benefits that could result from improved low-speed high-lift aerodynamic performance for a typical HSCT configuration during takeoff and initial climb.
Abstract: As part of an effort between NASA and private industry to reduce airport-community noise for high-speed civil transport (HSCT) concepts, a piloted simulation study was initiated for the purpose of predicting the noise reduction benefits that could result from improved low-speed high-lift aerodynamic performance for a typical HSCT configuration during takeoff and initial climb. Flight profile and engine information from the piloted simulation were coupled with the NASA Langley Aircraft Noise Prediction Program (ANOPP) to estimate jet engine noise and to propagate the resulting source noise to ground observer stations. A baseline aircraft configuration, which also incorporated different levels of projected improvements in low-speed high-lift aerodynamic performance, was simulated to investigate effects of increased lift and lift-to-drag ratio on takeoff noise levels. Simulated takeoff flights were performed with the pilots following a specified procedure in which either a single thrust cutback was performed at selected altitudes ranging from 400 to 2000 ft, or a multiple-cutback procedure was performed where thrust was reduced by a two-step process. Results show that improved low-speed high-lift aerodynamic performance provides at least a 4 to 6 dB reduction in effective perceived noise level at the FAA downrange flyover measurement station for either cutback procedure. However, improved low-speed high-lift aerodynamic performance reduced maximum sideline noise levels only when using the multiple-cutback procedures.
Journal Article•
TL;DR: In this article, the authors conducted noise measurement and social questionnaire surveys in three residential areas around Mehrabad International Airport (Tehran, Iran) based upon randomly selected dwellings in each area.
Abstract: Noise measurement and social questionnaire surveys in three residential areas around Mehrabad International Airport (Tehran, Iran) were based upon randomly selected dwellings in each area. A total of 193 individuals responded and many are annoyed and dissatisfied with aircraft noise and in consequence they would like to move. Aircraft noise is the strongest negative environmental factor affecting the residents in the vicinity of Mehrabad Airport and it could be a hazard for their health.
01 Dec 1999
TL;DR: In this article, a simulation study was performed for the purpose of indicating the noise reduction benefits and piloting performance that could occur for a typical 4-engine high-speed civil transport (HSCT) configuration during takeoff when a dual thrust cutback procedure was employed with throttle operation under direct computer control.
Abstract: A piloted simulation study was performed for the purpose of indicating the noise reduction benefits and piloting performance that could occur for a typical 4-engine high-Speed Civil Transport (HSCT) configuration during takeoff when a dual thrust-cutback procedure was employed with throttle operation under direct computer control. Two thrust cutbacks were employed with the first cutback performed while the vehicle was accelerating on the run-way and the second cutback performed at a distance farther downrange. Added vehicle performance improvements included the incorporation of high-lift increments into the aerodynamic database of the vehicle and the use of limited engine oversizing. Four single-stream turbine bypass engines that had no noise suppression of any kind were used with this configuration. This approach permitted establishing the additional noise suppression level that was needed to meet Federal Air Regulation Part 36 Stage 3 noise levels for subsonic commercial jet aircraft. Noise level results were calculated with the jet mixing and shock noise modules of the Aircraft Noise Prediction Program (ANOPP).
TL;DR: In this paper, the authors compared the results from a set of average flight paths for the situation of Zurich airport with two different methods for the data input to the noise calculation program.
Abstract: Aircraft noise calculations based on clusters of single flight events are compared to results from a set of average flight paths. For the situation of Zurich airport, the aircraft noise was calculated with two different methods for the data input to the noise calculation program. The traditional method consists of defining a main track and several side tracks, each associated with a specific percentage of traffic. Further, an average climb profile was defined for each aircraft type. The definition of these average flight paths is based on the analysis of radar information from the airport. The new method selects for a given aircraft and departure (or landing) procedure from all available radar data sets a representative sample of, e.g., 100 flights, including different seasons, different companies, and different take‐off weights. For each individual (real) flight the aircraft noise is calculated and the results are summed up according to the flight statistics. The price is an increase of computation load by a factor of 20, the benefit is a more representative result especially for regions with curved flights where the tracks diverge over a large area.
10 May 1999
01 Aug 1999
TL;DR: In the case of the main airport of the Netherlands, Amsterdam Shiphol Airport, the government imposes constraints on noise produced, the number of aircraft movements and passengers it is allowed to handle in a particular year.
Abstract: The growing air transport sector shows some of its more 'community unfriendly' faces through an increase in noise and burned fuel emissions on and in the vicinity of an airport. Protests from the surrounding community have put pressure on airport operators to decrease 'their' part in the amount of noise produced. In many instances this has led the airport operator to implement a policy to discourage airlines with noisy aircraft to fly into their airport. ICAO Annex 16, Chapter two aircraft are increasingly becoming more unpopular to operate from an airline's point of view due to these operating restrictions. However, community protest cannot ban all aircraft from an airport, not even in the Netherlands, but it can lead to constraints where it can virtually stop the possibility for airport growth. In the case of the main airport of the Netherlands, Amsterdam Shiphol Airport, the government imposes constraints on noise produced, the number of aircraft movements and the number of passengers it is allowed to handle in a particular year. These constraints are laid down in law. Without new operational ATC and flight procedures, the growth of Schiphol Airport would have come to a standstill with a few years. This paper describes the particular constraints Schiphol Airport has to live with, and the measures taken to overcome these constraints.
Journal Article•
TL;DR: In this paper, the authors conducted noise measurement and social questionnaire surveys in three residential areas around Mehrabad International Airport (Tehran, Iran) based upon randomly selected dwellings in each area.
Abstract: Noise measurement and social questionnaire surveys in three residential areas around Mehrabad International Airport (Tehran, Iran) were based upon randomly selected dwellings in each area. A total of 193 individuals responded and many are annoyed and dissatisfied with aircraft noise and in consequence they would like to move. Aircraft noise is the strongest negative environmental factor affecting the residents in the vicinity of Mehrabad Airport and it could be a hazard for their health.
TL;DR: In this paper, the authors compare the results of the FLULA2 point source simulation program with the measurements of single flight events and the measurements from monitoring stations around the airports to obtain the level-time history of a single flight.
Abstract: Aircraft noise predictions of the program FLULA2 are compared with airport noise monitor measurements and with single flight events. Further, the versatility of using a point source model for simulation is discussed and the implications of accurate noise predictions on land use planning are outlined. The aircraft noise simulation program FLULA2, developed at EMPA, uses a point source with a directivity characteristic in contrast to many other models which use line segments and correction terms. With the powerful model of a moving point source, the level‐time history of a single flight can be reconstructed. Thus all acoustic effects (topography, spectral air absorption, ground effects,...) may be included and any noise metrics can be calculated. The program is validated by comparing single events (the level‐time history of measurements and of calculations) and by comparing the yearly average of measurements at monitoring stations around airports with the Leq predictions. There are variations, but there is no systematic under‐ or overestimation of the noise calculations compared with the monitors.
TL;DR: In this paper, the authors explored the effect of a variety of possible approach flight procedures and concluded that the most promising procedures for alleviating approach noise in the areas some distance from an airport are the Continuous Descent and the Decelerating approaches.
Abstract: The use of larger aircraft and high-bypass engines has made the approach noise at airports more critical, but the methods used to control it rely on rather tenuous relationships between aircraft noise certification and the noise experienced by the communities around airports. Also, the options for alleviating approach noise are perceived to be fewer than for the takeoff case. The effect of a variety of possible approach flight procedures is explored. All of these procedures terminate in a conventional 3-degree final glide path, on the maximum noise levels under the flight path. In comparison, the effect of varying the glideslope angle on noise at the approach certification point is reported. It is concluded that the most promising procedures for alleviating noise in the areas some distance from an airport are the Continuous Descent and the Decelerating approaches. The current use of these techniques is limited by the incompatibility with air traffic control procedures. The more severe noise levels closer ...
TL;DR: In this paper, the psychoacoustic evaluation of noise emissions from road traffic noise, railway noise, aircraft noise, industrial noise, and leisure noise is discussed, and it is shown that the overall loudness of a noise emission is larger than the average of the instantaneous loudnesses of the acoustic events constituting the noise emission.
Abstract: While the psychoacoustic evaluation of noise emissions is already on its way from basic research laboratories in universities to application labs in industry, the psychoacoustic evaluation of noise emissions is not yet widely applied [http://www.mmk.e‐technik.tu‐muenchen.de/admin/noise.html]. Therefore, psychoacoustic evaluations of noise emissions from road traffic noise, railway noise, aircraft noise, industrial noise, and leisure noise are discussed. As a rule, the overall loudness of a noise emission is larger than the average of the instantaneous loudnesses of the acoustic events constituting the noise emission. With respect to physical measurements, statistical treatment of loudness values measured according to DIN 45 631 can predict the subjective evaluations of noise emissions for different types of noises. [Work supported by DFG.]