The landing approach for fixed-wing small unmanned air vehicles (SUAVs) in complex environments such as urban canyons, wooded areas, or any other obscured terrain is challenging due to the limited distance available for conventional glide slope descents. Alternative approach methods, such as deep stall and spin techniques, are beneficial for such environments but are less conventional and would benefit from further qualitative and quantitative understanding to improve their implementation. Flight tests of such techniques, with a representative remotely piloted vehicle, have been carried out for this purpose and the results are presented in this paper. Trajectories and flight data for a range of approach techniques are presented and conclusions are drawn as to the potential benefits and issues of using such techniques for SUAV landings. In particular, the stability of the vehicle on entry to a deep stall was noticeably improved through the use of symmetric inboard flaps (crow brakes). Spiral descent profiles investigated, including spin descents, produced faster descent rates and further reduced landing space requirements. However, sufficient control authority was maintainable in a spiral stall descent, whereas it was compromised in a full spin.
Non-CO2 aircraft emissions are responsible for the majority of aviation’s climate impact, however their precise effect is largely dependent on the environmental conditions of the ambient air in which they are released. Investigating the principal causes of this spatio-temporal sensitivity can bolster understanding of aviation-induced climate change, as well as offer potential mitigation solutions that can be implemented in the interim to low carbon flight regimes. This review paper covers the generation of emissions and their characteristic dispersion, air traffic distribution, local and global climate impact, and operational mitigation solutions, all aimed at improving scientific awareness of aviation’s non-CO2 climate impact.
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