More & less

MORE&LESS (MDO and REgulations for Low boom and Environmentally Sustainable Supersonic aviation), answering to the EC call “Towards global environmental regulation of supersonic aviation” (LC-MG-1-15-2020), aims at supporting Europe to shape global environmental regulations for future supersonic aviation: recommendations are established on the basis of the outcomes of extensive high-fidelity modelling activities and test campaigns that merge into the multi-disciplinary optimization framework to assess the holistic impact of supersonic aviation onto environment.


To seek this goal, MORE&LESS addresses the following objectives:

MORE&LESS aims at assessing the entire spectrum of supersonic speed regime, conventionally ranging from Mach 2 to Mach 5, looking at the most promising aircraft
configurations, propulsive technologies and fuels. Indeed, considering the importance of increasing the environmental sustainability of supersonic aviation, the analysis is not only restricted to aircraft using traditional hydrocarbon fuel but it moves beyond, addressing aircraft concepts that exploit alternative fuels, such as bio-fuels
and liquid hydrogen, the so called Sustainable Aviation Fuels (SAF). In this scenario, the establishment of international cooperation has been considered strategic to select a set of real up-to-date case studies summarizing the worldwide current status of research activities in the field of supersonic aviation.

MORE&LESS pursues this objective by verifying the compliance of supersonic aircraft with the environmental requirements of current and next-generation civil subsonic aircraft or by assessing potential new supersonic transport standards. Aircraft configurations, propulsive technologies, types of fuel and aircraft trajectories and operations play a crucial role in the capability of fulfilling the environmental requirements. MORE&LESS addresses this issue and indicates which are the aircraft configurations, the propulsive technologies, the types of fuel and trajectories and operations that help match the requirements, thus allowing for the minimum
environmental impact.
In details, MORE&LESS aims at verifying the possibility for supersonic aviation to fulfil the following requirements and provide information to relevant international working groups, i.e. CAEP Working Group (WG) 1 and WG3:

  • To provide potential noise-power-distance data, LTO noise and en-route noise (sonic boom intensity PLdB) estimations
  • Noise emissions (in EPNdB) compatible with Chapter 4 Noise limits (Chapter 4 cumulative level 275.2 EPNdB, 80 dB SEL) (ICAO CAEP Annex 16 Vol I)
  • To provide estimates on LTO and cruise pollutant emissions: Pollutant emissions (oxides of nitrogen (NOx) as in ICAO CAEP/8 limits, and non-volatile particulate matter (nvPM) compatible with new standards CAEP/11. CO2 standard to be in line with existing Annexe 16, Vol III (at both subsonic and supersonic speeds)

MORE&LESS pursues this objective by transposing the scientific findings in the fields of aerodynamics, aeroacoustics, propulsion, pollutant emissions and environmental impact into guidelines to support the Regulatory Community to shape policy and regulations for the future supersonic aviation according to solid technical bases. In this context, MORE&LESS aims at developing a holistic framework able to assess the environmental impact of supersonic aviation at local, regional and global levels through a multidisciplinary approach, which encompasses the different disciplines and their mutual relationships, thus allowing to perform a multi-objective optimization of supersonic aircraft’ trajectories and operations. Thanks to low and high-fidelity modelling activities and test campaigns, already existing accepted and validated software tools, that constitute the basic bricks of the holistic framework, are enhanced and extended to cover supersonic aviation. The application of the multidisciplinary holistic framework to the case-studies is the proving ground to verify that the enabling technologies of supersonic aircraft, their trajectories and operations comply with the environmental requirements, thus validating the concepts, trajectories and operations of future supersonic aviation. The definition of recommendations to support the review of regulations and procedures to fit future supersonic aviation into the airspace stem directly from the results of the application of the multidisciplinary holistic framework, thus exploiting solid and robust technical bases. To guarantee the fulfilment of this objective, MORE&LESS includes representatives of the Regulatory Community as members of the Expert External Advisory Board (EEAB) (EUROCONTROL, ENAC, EASA and FAA) to provide feedbacks throughout the project and to acknowledge all the technical findings and derived suggestions for the definition of regulations and procedures to be adopted for the future supersonic aviation.

MORE&LESS pursues this objective:
by enhancing the understanding of not yet fully understood physical phenomena in the field of sonic boom, jet noise, pollutant emissions and environmental impact. The target is to increase the Technology Readiness Levels of these disciplines from TRL from 1 to 2, through basic research activities;
by increasing the accuracy of predictive models in the field of aerodynamics, propulsion, aeroacoustics (encompassing both sonic boom and jet-noise), pollutant emissions and environmental impact (including atmospheric modelling, air quality, ozone layer and climate impact), through applied research activities. The target is to increase the Technology Readiness Levels of such disciplines from TRL 2 to TRL 3;
by validating predictive models and simulations through dedicated tests campaigns in the field of propulsion, aerodynamics, jet noise and pollutant emissions. The target is to increase the Technology Readiness Levels of such disciplines from 3 to 4 thanks to tests in laboratories and in the field of sonic boom from TRL 4 to TRL 5 thanks to tests in relevant environment;
by understanding all the interrelated effects of physical phenomena, trajectories and operations onto the environmental impact through the development of a multidisciplinary holistic framework. In particular, thanks to technology development and integration of validated models into software tools to properly capture propulsion, aerodynamics, sonic boom, jet noise, pollutant emissions and environmental impact of supersonic aviation, MORE&LESS aims at increasing the Technology Readiness Level of the stand-alone tools and the unique framework from TRL 5 to TRL 6.

MORE&LESS aims at pursuing this objective by including two US aircraft companies that are world-wide leaders in the field of supersonic aviation. US partners provide the consortium with real case-studies to be further analysed and allow for the definition of commonly agreed regulations for the future supersonic aviation. During the project the EEAB is planned to be enlarged to include also representative of international bodies for aviation certifications and regulations, i.e. FAA, based on currently positive on-going contacts and feedbacks through US international partners.

through dedicated dissemination actions including public educational events, Lecture Series, Summer Schools and dedicated Doctoral Courses at Engineering Faculties.


The project activities are implemented through 7 Work Packages (WP):

  • WP1 – Project Management, dissemination, communication and exploitation: POLITO (Prof. Nicole Viola)
  • WP2 – Case-studies analysis: configuration, performance and operations: POLITO (Prof. Nicole Viola)
  • WP3 – Aerodynamics and Aeroacoustics: prediction models and test campaigns: CIRA (Dr. Marco Marini)
  • WP4 – Propulsion and pollutant emissions: prediction models and test campaigns: IVKDF (Dr. Bayindir H. Saracoglu)
  • WP5 – Air Quality, Ozone Layer and Climate impact prediction models: DLR (Prof. Volker Grewe)
  • WP6 – Holistic framework for environmentally sustainable supersonic aviation: POLITO (Dr. Roberta Fusaro)
  • WP7– Guidelines for an update of the Regulatory Framework: ENVISA (Dr. Ayce Celikel)