Preliminary noise assessment of aircraft with distributed electric propulsion

Electric and hybrid-electric propulsion technologies in aviation are becoming more attractive for aviation stakeholders not only due to the resulting reduction or elimination of the dependency on oil, whose availability and price are uncertain, but also because they are more reliable and efficient than traditional internal combustion engines. Moreover, combined with distributed electric propulsion (DEP), these technologies have shown potential in significantly reducing civil aircraft community noise impact and contribute towards delivering the strict mid-to-long-term environmental goals set by organisations worldwide, such as ACARE and NASA. This paper examines the noise impact of a concept tube and wing aircraft that falls in the A320 category and features various DEP systems using different power supply units (turboshaft engines or batteries) and number of electric propulsors. Meanwhile, considerations required for the transition from conventional to electric propulsion are discussed. Estimated Noise-Power-Distance (NPD) curves and noise exposure contour maps are also presented. It is concluded that indeed, the propulsors’ number is a key parameter for optimising the environmental performance of DEP aircraft and hence maximising the noise benefits. Also, it is shown that based on the entry into service year (2035) technology, totally electric aircraft tend to have a larger noise footprint than aircraft using hybrid electric propulsion systems

Ground-based wake vortex prediction in the en-route european airspace

The present study deals with ground-based prediction of en-route wake turbulence encounters in the European airspace. Due to an increasing overall volume of air traffic with required navigation performance within highly congested en-route airspaces, wake turbulence encounters above flight level 100 are becoming more frequent during the last years. The prediction of en-route wake vortex encounters provides information about airspaces with an increased encounter probability as well as specific characteristics of potential encounters. Apart from safety-related benefits, this information may be applied during flight-and capacity planning processes. Two different types of models are coupled with each other: an air traffic flow management model and a wake vortex decay and transport model. The results provide information about the predicted number of en-route encounters, dominant spatial encounter configurations and their locations

Characterizing UAS collision consequences in future UTM

UAS will be integrated into the airspace in the near future, but the risk of UAS collision is not well understood which hampers the development of adequate regulations and standards. As risk has two constituents: frequency and consequence, collision risk analysis of UAS operations in future UTM asks for a quantitative assessment of various types of frequency and consequence. However, prior to studying such quantitative assessment, it is a prerequisite to identify the various types of collisions and consequences. Doing the latter is the objective of this paper. This paper follows a step-wise approach in identifying the various types of collision consequence under a given UTM ConOps, focusing on the very-low-level UAS operations. The first steps address the analysis of the UTM ConOps, rules, and infrastructure considered, and the identification of types of objects and UASs that will operate in the very-low-level UTM system. The follow-up steps are to characterize impact materials by applying zone of impact analysis, followed by analyzing the types of collision consequence. The result is a systematic identification and characterization of types of collision consequences as well as applicable impact materials and conditions that will form the basis for safety risk analysis in follow-on research.Aerospace Transport & OperationsStructural Integrity & CompositesControl & Simulatio

Effects of pushback accuracy on static apron capacity

The static apron capacity for aircraft with a wingspan higher than 65m is limited at Amsterdam Airport Schiphol (AMS). With the introduction of new large aircraft with increasing wingspan, such as the B777-9X, Schiphol is faced with the challenge of realizing larger gates. Currently, the taxi wingtip clearance is used for pushback and towing and the goal of this research is to see if it is possible to decrease the wingtip clearance there. Using aircraft transponder data and reproducing the pushback tracks for five gates, it is shown that some room is available to limit clearance and thus increase capacity at some gates, but more capacity could be gained by providing tug drivers with extra guidance through Differential GPS or a ‘Follow the Greens’ system.Aerospace Transport & Operation