**Preface to "12th EASN International Conference on Innovation in Aviation & Space for Opening New Horizons"**

This Special Issue features selected papers presented at the 12th EASN International Conference on "Innovation in Aviation & Space to the Satisfaction of the European Citizens" (https://easnconference.eu/2022/home), which took place successfully from October 18th to 21st, 2022, in Barcelona. The conference included 8 keynote lectures delivered by distinguished personalities from the European Aviation & Space Community, along with 395 technical presentations spread across 74 virtual sessions. Notably, 85 Aviation and Space projects showcased their latest research findings and future trends in their respective technological domains during the conference. The 12th EASN International Conference garnered considerable interest and active engagement, attracting a remarkable turnout of over 470 participants representing 39 countries from around the world.

Out of the numerous submissions received during the 12th EASN Virtual Conference, a total of 20 papers have been selected for publication in this Special Issue.

Focusing on the theme of sustainable aviation and infrastructure, in [1], promising technologies, such as a wingtip propeller and electric green taxiing, are discussed, and their potential impacts on the future of aviation are highlighted. In [2], The development and implementation of the GreAT (Greener Air Traffic Operations) concept within the DLR realtime simulation environment ATMOS is realised. In [3], the results of an energy demand analysis for a future regional airport over three different time horizons are presented.

Focusing on safety and performance analysis, in [4], a methodology has been developed in order to optimize the structure of the parachute harness with the purpose of lightening it. [5] aims to establish capacity models that consider the neurophysiological variables recorded during the development of ad hoc real-time simulation exercises designed for the CRITERIA project. In [6], the impact of nanosecond pulse discharge NSPD on enhancing the flame propagation of CH4/H2/air mixture under ambient temperature and pressure is investigated.

With regard to aviation technologies and innovations, [7] presents the extension of an approach controller support system for diversions around severe weather areas. Within [8], a procedure is developed which enables an efficient design of interface-modified CFRP under impact loads. The aim of [9] is to simultaneously improve the duct's pressure loss and flow distortion under three flight conditions: nominal cruise, low-altitude climbing, and high-altitude cruise.

Focusing on aircraft design and materials, [10] describes the definition and application of the technology evaluation stage of the Advanced Morphological Approach AMA design process based on expert workshops. In [11], different mixtures of both milled and unmilled Cp-Ti grade 2 powder were utilized using the PM method, aiming to synthesize samples with high mechanical properties comparable to those of high-strength alloys. Within [12], the authors focus on the results of the preliminary activities performed within the CleanSky 2/Astib research program, dedicated to the definition of the iron bird of a new regional-transport aircraft. Within [13], a volume coefficient-based vertical tail plane sizing is compared to handbook methods and the possibility to reduce the necessary vertical stabilizer size is assessed with regard to the position of the engine integration and their interconnection.

With regard to advanced technologies and applications, [14] develops a methodology in which the final result is a machine learning model that allows predicting capacity regulations. In [15], a set of three different metaheuristic search algorithms have been considered for failure detection and identification purposes. [16] describes the multidisciplinary design of an aerodynamic drag device used to allow a passive re-entry, i.e., avoiding retropropulsion, of a reusable launch vehicles' first stage. In [17], the robustness of a hybrid MCDM tool to support the selection of sustainable materials in aviation has been assessed. In [18], a rapid and robust sizing methodology is presented, along with a comparative study on the impact of energy source configurations, on the autonomy of a multirotor aerial vehicle. The authors of [19] deal with developing a self-healing resin designed for aeronautical and aerospace applications. Finally, [20] demonstrates the competitive properties of a manufactured part, produced using laser powder bed fusion (LPBF), using a specific build orientation.

The editors of this Special Issue extend their appreciation to the authors for their excellent contributions and for greatly assisting in managing this Special Issue. Additionally, the editors would like to express their gratitude to Ms. Linghua Ding and the Aerospace editorial team for their valuable professional support.
