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Supersonic civil aircraft present a unique noise certification challenge. High specific thrust required for supersonic cruise results in high engine exhaust velocity and high levels of jet noise during take-off. Aerodynamics of thin, low-aspect-ratio wings equipped with relatively simple flap systems deepen the challenge. Advanced noise reduction p...
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Context 1
... and climb at high speed may be preferred for many supersonic aircraft. This preference can be shown for the supersonic business jet in this study by constructing its thrust demand curves. These are shown in Fig. 4 for level and steady flight at maximum weight using take-off flaps at an altitude of 600 meters. Unlike a medium subsonic commercial aircraft of similar weight in these conditions, which may have a minimum drag speed of perhaps 200 Kn, our supersonic business jet's minimum drag speed is predicted to be nearly 300 Kn. Speeds below the minimum drag speed are in the so-called region of reversed command, where to fly more slowly requires more thrust to overcome increasing lift-dependent drag. Flying safely in this region requires adequate thrust margins. If climb-out speeds are limited by 3.6.2(d)(1) of Ref. 1, very high rotation and lift-off speeds would seem to be in order, so that the climb- out would take place at as high a speed as possible. Since modern aircraft tires are rated to Noise predictions for a supersonic business jet… Even so, 202 Kn is still well inside the region of reversed command. This demonstrates the need for high-speed ground rolls (delayed rotations) and quite possibly an accelerating climb- out. Seemingly, an excellent case could be made to permit a departure from the climb-out speed limit requirement defined by 3.6.2(d)(1) of Ref. ...
Context 2
... and climb at high speed may be preferred for many supersonic aircraft. This preference can be shown for the supersonic business jet in this study by constructing its thrust demand curves. These are shown in Fig. 4 for level and steady flight at maximum weight using take-off flaps at an altitude of 600 meters. Unlike a medium subsonic commercial aircraft of similar weight in these conditions, which may have a minimum drag speed of perhaps 200 Kn, our supersonic business jet's minimum drag speed is predicted to be nearly 300 Kn. Speeds below the minimum drag speed are in the so-called region of reversed command, where to fly more slowly requires more thrust to overcome increasing lift-dependent drag. Flying safely in this region requires adequate thrust margins. If climb-out speeds are limited by 3.6.2(d)(1) of Ref. 1, very high rotation and lift-off speeds would seem to be in order, so that the climb- out would take place at as high a speed as possible. Since modern aircraft tires are rated to Noise predictions for a supersonic business jet… Even so, 202 Kn is still well inside the region of reversed command. This demonstrates the need for high-speed ground rolls (delayed rotations) and quite possibly an accelerating climb- out. Seemingly, an excellent case could be made to permit a departure from the climb-out speed limit requirement defined by 3.6.2(d)(1) of Ref. ...
Context 3
... and climb at high speed may be preferred for many supersonic aircraft. This preference can be shown for the supersonic business jet in this study by constructing its thrust demand curves. These are shown in Fig. 4 for level and steady flight at maximum weight using take-off flaps at an altitude of 600 meters. Unlike a medium subsonic commercial aircraft of similar weight in these conditions, which may have a minimum drag speed of perhaps 200 Kn, our supersonic business jet's minimum drag speed is predicted to be nearly 300 Kn. Speeds below the minimum drag speed are in the so-called region of reversed command, where to fly more slowly requires more thrust to overcome increasing lift-dependent drag. Flying safely in this region requires adequate thrust margins. If climb-out speeds are limited by 3.6.2(d)(1) of Ref. 1, very high rotation and lift-off speeds would seem to be in order, so that the climb- out would take place at as high a speed as possible. Since modern aircraft tires are rated to Even so, 202 Kn is still well inside the region of reversed command. This demonstrates the need for high-speed ground rolls (delayed rotations) and quite possibly an accelerating climb- out. Seemingly, an excellent case could be made to permit a departure from the climb-out speed limit requirement defined by 3.6.2(d)(1) of Ref. ...
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Citations
... Conversely, for supersonic aviation standards, flight procedures have not been defined yet. However, in order to guarantee an adequate public consensus towards future SSTs, the scientific community is anticipating the possibility of extending the current subsonic flight procedures to civil supersonic aircraft [86]. The section for newer supersonic aeroplanes only contains a note that standards and recommendations for SST have not been developed yet, but maximum noise levels from subsonic jet aeroplanes could be used as guidelines. ...
The request for faster and greener civil aviation is urging the worldwide scientific community and aerospace industry to develop a new generation of supersonic aircraft, which are expected to be environmentally sustainable, and to guarantee a high level of protection for citizens. The availability of novel propulsive technologies, together with the development of new civil supersonic passenger aircraft configurations and missions, is pushing international authorities to update the regulatory framework to limit nuisances on the ground and the contribution to climate change. Existing ICAO noise and emissions standards are outdated as they were developed in the 1970s and tailored to Concorde, the only SST that has ever operated in Western airspace. This article provides (i) a comprehensive review of current environmental regulations for SST, encompassing noise and pollutant emissions near airports (LTO cycle) as well as CO2 emissions and sonic booms, and (ii) updated information about the ongoing rulemaking activities by ICAO, FAA and EASA. This review clearly highlights the following findings: (i) the need to revise current rules to better fit future SST design, operations and technologies; (ii) the need to introduce new regulations to cover additional aspects, including stratospheric water vapour emissions and ozone depletion; and (iii) the need to support regulatory activities with solid technical bases, fostering cooperation with academia, research centres and industry in R&D projects. Eventually, a practical example of how SST rulemaking activities are supported by the collaborative research H2020 MORE&LESS is reported.
... In order to ensure the noise certification of novel SST vehicles, available and newly designed noise reduction technology should be implemented. Various numerical studies in that field are documented by NASA [8][9][10][11], JAXA [12,13], Cranfield University [14], TsAGI [15], and Uni Turino with CIRA [16] investigating the landing and take-off (LTO) noise of supersonic aircraft † . The listed studies identify the impact of different take-off procedures and showed a benefit for an advanced noise abatement take-off procedure with a programmed thrust lapse rate (PLR) and a high-speed climb-out. ...
... One of the primary issues identified during the Concorde era was the significant noise impact near airport areas, which far exceeds that of subsonic aircraft. Advanced propulsion systems and flight procedures have been and are investigating as possible methods to mitigate the noise footprint resulting from supersonic aircraft [8,9,10]. Nonetheless, the development of an up-to-date regulatory framework for supersonic aircraft remains uncertain, and the regulatory status of potential civil hypersonic aircraft is even more up in the air. ...
... The influence that supersonic airplanes are expected to have on operations, fuel consumption, airport noise, and air quality were assessed. Since then, the STCA continues to serve as a notional reference airplane used in studies conducted by NASA [3][4][5][6][7] and by others [8][9][10][11][12][13][14][15]. This paper documents an additional NASA study using the STCA. ...
... The design of the VNRS procedure is important because the takeoff profile and engine power settings significantly influence noise during takeoff. As in previous NASA STCA studies [3][4][5], all takeoff profiles are computed using a forward-differencing trajectory solver [22]. Calculations assume a sea level runway and use standard acoustic day conditions. ...
A variable noise reduction system consists of equipment on board an airplane that is designed to reduce noise in the vicinity of airports. They are anticipated to be used on supersonic civil aircraft currently under development by industry. They are investigated in this paper for a notional 55,000 kg supersonic business jet. The airplane concept was developed by NASA for use in environmental impact studies conducted by the International Civil Aviation Organization. The variable noise reduction system investigated implements a programmed thrust lapse procedure and a programmed flap retraction procedure. The procedures are expected to reduce noise in aircraft certification as well as in operational practice. Behavior of the aircraft in a noise certification setting is considered. Variables of the procedures are optimized to reduce noise levels. The optimization results in a reduction of 5.2 decibels (in the cumulative effective perceived noise level, measured in EPNdB) relative to levels reported previously. Certification considerations unique to these systems are discussed for transport-category large airplanes and jet-powered airplanes. A novel method for evaluating lateral noise is used.
... In addition to sonic boom, papers have explored noise prediction and/or reduction. Researchers have examined methods for the fuselage's (Hanson, 1984;Holmer Holmer, 1985;Jones, and Fuller, 1988;Clark and Gibbs 1999;Warwick et al., 2020) or aircraft's noise reduction (Tyacke et al., 2017;Berton et al., 2018;Broatch et al., 2019;Khorrami and Fares, 2019), mechanisms of creation of aircraft's noise (Fink, 1979;Dobrzynski, 1981) or aeroacoustic phenomena characteristic of a pusher-propeller configuration and their aerodynamic causes (Yin et al., 2012). On the other hand, attention has attracted, both in Applied and in Natural Sciences, the estimation of aircraft's environmental emissions (Hu et al., 2009;Durdina et al., 2019;Kozlova et al., 2021;Sun and Smith, 2021;Weit et al., 2021) partnered with all-electric propulsion systems (Lukasik and Wisniowski, 2017), a methodology applicable in multi-disciplinary optimisation during aircraft pre-design for mitigation of aircarft's environmental impact (Grewe et al., 2010) and the introduction of ideas and technologies for a conceptual and aerodynamic design of a green business jet aircraft (Djojodihardjo, 2018). ...
Unlike the other air transport business models, air cargo and business aviation proved resilient during the COVID-19 pandemic setting the fundamentals for further growth in the post-pandemic business environment. In contrast to air cargo, however, business aviation is relatively under-researched. On these grounds, this paper is of interest as it examines the available academic contributions on business aviation using a systematic literature review methodology. Based on Scopus, Transportation Research International Documentation (TRID) and Web of Science databases and after applying specific inclusion criteria, 260 papers were selected for further analysis. We performed a descriptive analysis to identify the basic characteristics of the papers and a content analysis with VOSviewer software to comprehend deeply the arguments that have been investigated so far. We found that the first paper was published in 1966 and until 2021 there is a steady but slow increase in the scientific research mainly in four disciplines: Applied Sciences (70.00%), Economic and Social Sciences (18.46%), Natural Sciences (9.23%) and Health Sciences (2.31%). There are 637 researchers working in affiliations located in 37 countries that have studied business aviation-related issues. Nevertheless, they have formed small networks within their country or affiliation's boundaries. United States is the country that leads the research on business aviation in terms of publications and unique researchers' affiliations while University of Quebec from Canada is the leading affiliation with the highest number of publications. The content analysis showed that business aviation research is limited to a few topics among which engineering management aspects have mostly been explored. Overall, the results show that much room exists for future research on business aviation especially with respect to economics and business management issues, environmental impacts, and health-related topics.
... The influence that supersonic airplanes are expected to have on operations, fuel consumption, airport noise, and air quality were assessed. Since then, the STCA continues to serve as a notional reference airplane used in studies conducted by NASA [3][4][5] and by others [6][7][8][9][10][11][12][13]. This paper documents an additional NASA study using the STCA. ...
... The design of the VNRS procedure is important since the takeoff profile and engine power settings significantly influence noise during takeoff. As in previous NASA STCA studies [3][4][5], all takeoff profiles are computed using a forward-differencing trajectory solver [30]. Calculations assume a sea level runway and use standard acoustic day conditions. ...
A variable noise reduction system consists of equipment on board an airplane that is designed to reduce noise in the vicinity of airports. They are anticipated to be used on supersonic civil aircraft currently under development by industry. They are investigated in this paper for a notional 55-tonne supersonic business jet. The airplane concept was developed by NASA for use in environmental impact studies conducted by the International Civil Aviation Organization. The variable noise reduction system investigated implements a programmed thrust lapse procedure and a programmed flap retraction procedure. The procedures are expected to reduce noise in aircraft certification as well as in operational practice. Behavior of the aircraft in a noise certification setting is considered. Variables of the procedures are optimized to reduce noise levels. Certification considerations unique to these systems are discussed for transport-category large airplanes and jet-powered airplanes. A novel method for evaluating lateral noise is used.
... NASA began work on the STCA in 2017 in support of ICAO. Since then, the STCA continues to serve as a notional reference airplane used in studies conducted by NASA [1][2][3] and by others [4][5][6][7][8][9][10][11]. Aircraft mission performance, airport-vicinity noise, and exhaust emissions are predicted for the STCA using NASA tools. ...
The International Civil Aviation Organization recently completed a study that determined the global environmental impact of adding several hypothetical supersonic aircraft types to the existing subsonic fleet. NASA supported this study by designing a notional 55-tonne supersonic business jet. The airplane is named the Supersonic Technology Concept Aeroplane by the international community. Performance, noise, and exhaust emission predictions for this transport were used to inform development of new environmental standards for future supersonic civil aircraft. The behavior of the aircraft in an operational setting is considered. Calculation of aircraft noise and performance data for this aircraft is the focus of this paper. Noise abatement departure procedures, stage length performance, and noise-power-distance data are determined using NASA tools. Also investigated are some of the anticipated behaviors and requirements of supersonic aircraft in the commercial airspace.
... The previous Section demonstrates that the concept of next-generation supersonic civil aircraft needs modifications to reach the objective of complying with Chapter 14 for subsonic aircraft. Some additional benefits can be obtained by utilizing advanced departure procedures such as "programmed lapse rate"; estimates by NASA for the STCA concept for supersonic civil aircraft demonstrated that implementation of such procedures reduced the cumulative noise level by 4 EPNdB [23]. Still, achieving this objective is a formidable technical problem, which is reflected in the proposed U.S. norms for supersonic civil aircraft by FAA [24]. ...
Compliance with environmental protection regulations, in particular, community noise requirements, constitutes one of the major obstacles for designing future supersonic civil aircraft. Although there are several noise sources that contribute to the total noise level of supersonic aircraft, it is the turbulent jet that appears most problematic; jet noise is a dominant noise source for low-to moderate- bypass-ratio engines, and at present there are no effective methods of jet noise reduction other than decreasing jet speed by increasing bypass ratio, which, in turn, is constrained by aerodynamic requirements for supersonic flight. The present study considers a concept of supersonic civil aircraft under the assumption that its total noise is determined by turbulent jets; it is shown that compliance of the supersonic aircraft with the current regulations for subsonic aircraft noise (Chapter 14 Volume I Annex 16 ICAO) would require the decreased jet speed that corresponds to a prohibitively high bypass ratio of aircraft engines. To enable jet noise reduction without necessarily increasing bypass ratio, a novel configuration of supersonic aircraft is proposed that meets the requirements of Chapter 14, thereby demonstrating that the norms of Chapter 14 are achievable for future supersonic civil aircraft with the use of existing technologies.
... However, significant differences exist between supersonic and subsonic aircraft, so up-to-date noise standards could not be appropriate for the supersonic case. Therefore, dedicated studies are being undertaken towards the identification of advanced departure and approach flight procedures aimed at reducing noise especially for take-off conditions [29][30][31]. ...
... Conversely, for supersonic aviation standards, flight procedures have not been defined yet. However, in order to guarantee an adequate public consensus towards the future SSTs, the scientific community is anticipating the possibility of extending the current subsonic flight procedures to civil supersonic aircraft [31]. In parallel, the regulatory community is foster-ing research activities aimed at investigating the technical and technological limitations to the application of already existing flight procedures to SSTs [29,30]. ...
One of the most critical regulatory issues related to supersonic flight arises from limitations imposed by community noise acceptability. The most efficient way to ensure that future supersonic aircraft will meet low-noise requirements is the verification of noise emissions from the early stages of the design process. Therefore, this paper suggests guidelines for the Landing and Take-Off (LTO) noise assessment of future civil supersonic aircraft in conceptual design. The supersonic aircraft noise model is based on the semi-empirical equations employed in the early versions of the Aircraft NOise Prediction Program (ANOPP) developed by NASA, whereas sound attenuation due to atmospheric absorption has been considered in accordance with SAE ARP 866 B. The simulation of the trajectory leads to the prediction of the aircraft noise level on ground in terms of several acoustic metrics (LAmax, SEL, PNLTM and EPNL). Therefore, a dedicated validation has been performed, selecting the only available supersonic aircraft of the Aircraft Noise and Performance database (ANP), that is, the Concorde, through the matching with Noise Power Distance (NPD) curves for LAmax and SEL, obtaining a maximum prediction error of ±2.19%. At least, an application to departure and approach procedures is reported to verify the first noise estimations with current noise requirements defined by ICAO at the three certification measurement points (sideline, flyover, approach) and to draw preliminary considerations for future low-noise supersonic aircraft design.
... This procedure has become known as the autothrottle or PLR takeoff [33]. In the U.S.A., regulatory standards are being considered to accommodate this procedure for new supersonic transports through a provision known as a variable noise reduction system [34][35][36]. ...
