The impact of contrails on Earth’s climate is probably not negligible, yet there are only a few initiatives aimed at mitigating the influence of aviation on the environment. To achieve zero CO2 emissions, aircraft manufacturers and airlines propose complex and costly methods and technologies such as synthetic fuels, hybrid engines, or expensive carbon offsetting. On the other hand, contrail mitigation by achievable operational measures has the potential to achieve benefits with a very positive cost-benefit ratio without the need for a complex technological change in aviation. It seems that one suitable tool for contrail mitigation is the change in flight level. Therefore, we focused on the assessment of flight levels with typical contrails occurrence and common flight levels used by air traffic management. Some influence of tropopause height throughout the year was presumed to be a factor, therefore we studied different times of the year. The tropopause height influences not only contrail occurrence but also the preferred flight level, as airlines tend to avoid flying directly in the tropopause. We present some basic statistics about the frequency of contrail occurrence based on flight level. We focused on long-lived contrails to emphasize the more important contrails in this context. Information about flight levels is based on ADS-B data transmitted by aircraft and recorded by a ground station near the place of contrail occurrence, which was based on optical survey.
The purpose of this paper is to describe the upcoming changes that will bring the transition from piston engines to all-electric aircrafts. The article focuses on the differences in operation of small general aviation aircrafts. This topic is timely, as the first all-electric aircraft was certified by the European Union Aviation Safety Agency (EASA) in 2019. As there are no data concerning this new type of operation available, the data have been derived from other applicable sources. At first, we compared the energy consumption of the same aircraft with the piston engine, and then afterwards with the retrofitted all-electric variant. Our results focus on the difference in fuel price, which is discussed in the context of electricity price comparison with AVGAS prices. Moreover, we discuss the environmental impacts, especially concerning electricity source mix and emissions produced (we estimate both with and without life-cycle assessment). In the discussion, we compare the results and identify the benefits of an all-electric solution. Furthermore, several operational restrictions of all-electric aircrafts are discussed.
<span style="font-family: 'Times New Roman','serif'; font-size: 10pt; mso-fareast-font-family: 'MS Mincho'; mso-ansi-language: EN-GB; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;" lang="EN-GB">The paper summarizes changes in the flight planning caused by the introduction of Free Route Airspace Project and suggests possible measures needed to be adopted across the whole system in order to ensure military and civilian aircraft remain segregated in a way that is today ensured by the system of conditional routes. The paper suggests a possible solution in flight planning using existing flight planning tools provided by the CFMU.</span>
The paper focuses on reusable launch space systems. It aims to describe the current state of reusability in space systems and to analyze the launch cost of current Falcon carrier rockets.<br />The first chapter is dedicated to general information about reusable launch space systems. This includes definition of reusable and expendable launch systems or history of reusable launch systems. The second part is focused on the era after STS and new the concept of RLV. The following parts of this paper aim to analyze the launch price of current Falcon carrier rockets.
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