Commercial and private deployment of airborne drones is revolutionising many ecosystems. To identify critical issues and research gaps, our systematic literature review findings suggest that historic issues such as privacy, acceptance and security are increasingly replaced by operational considerations including interaction with and impacts on other airspace users. Recent incidents show that unrestricted drone use can inflict problems on other airspace users like airports and emergency services. Our review of current regulatory approaches shows a need for further policy and management response to both manage rapid and efficient drone usage growth, and facilitate innovation (e.g. intraurban package delivery), with one promising strategic response being low altitude airspace management (LAAM) systems for all drone use cases.The current outbreak of COVID-19 is an unprecedented event in air transportation. This is probably the first time that global aviation contributed to the planet-wide spread of a pandemic, with casualties in over two hundred countries. As of August 23rd, 2020, the number of infected cases has topped 23 million, reportedly relating to more than 800,000 deaths worldwide. However, there is also a second side of the pandemic it has led to an unmatched singularity in the global air transportation system. In what could be considered a highly uncoordinated, almost chaotic manner, countries have closed their borders, and people are reluctant/unable to travel due to country-specific lock-down measures. Accordingly, aviation is one of the industries that has been suffering most due to the consequences of the pandemic outbreak, despite probably being one of its largest initial drivers. In this study, we investigate the impact of COVID-19 on global air transportation at different scales, ranging from worldwide airport networks where airports are nodes and links between airports exist when direct flights exist, to international country networks where countries are contracted as nodes, and to domestic airport networks for representative countries/regions. We focus on the spatial-temporal evolutionary dynamics of COVID-19 in air transportation networks. Our study provides a comprehensive empirical analysis on the impact of the COVID-19 pandemic on aviation from a complex system perspective using network science tools.This paper addresses the airplane passengers' seat assignment problem while practicing social distancing among passengers. We proposed a mixed integer programming model to assign passengers to seats on an airplane in a manner that will respect two types of social distancing. One type of social distancing refers to passengers being seated far enough away from each other.  https://www.selleckchem.com/products/BIBF1120.html  The metric for this type of social distancing is how many passengers are seated so close to each other as to increase the risk of infection. The other type of social distancing refers to the distance between seat assignments and the aisle. That distance influences the health risk involved in passengers and crew members walking down the aisle. Corresponding metrics for both health risks are included in the objective function. To conduct simulation experiments, we define different scenarios distinguishing between the relative level of significance of each type of social distancing. The results suggest the seating assignments that best serve the intention of the scenarios. We also reformulate the initial model to determine seat assignments that maximize the number of passengers boarding an airplane while practicing social distancing among passengers. In the last part of this study, we compare the proposed scenarios with the recommended middle-seat blocking policy presently used by some airlines to keep social distancing among passengers. The results show that the proposed scenarios can provide social distancing among seated passengers similar to the middle-seat blocking policy, while reducing the number of passengers seated close to the aisle of an airplane.This paper analyses the price responses of airports to a demand collapse, such as that prompted by Covid-19. In the crisis, airports need to achieve viability, in the short run through sufficient liquidity, and in the long run, by covering costs. From a public policy viewpoint, price increases in a crisis are argued to be undesirable, as they would further jeopardise the viability of airlines and tourism as well as the wider economic transport benefits such as connectivity. The institutional environment of airports differs from airport to airport; some are publicly owned, others are private but regulated, and others face competition. The price response of each (of 6) types of airport is considered, and how policy could respond to keep prices low in the crisis while ensuring longer term viability. Regulated airports could defer price increases until demand had recovered, if regulators insisted they do so. Publicly-owned airports could be directed by governments to keep charges low. Governments might also state that unregulated airports that raised charges could be made subject to price regulation in the future. Competitive airports would be unable to raise charges but this could jeopardise their viability. In this case and others where airports might need financial assistance, assistance could be made conditional on keeping charges low in the crisis.This paper assesses government support measures to the air transport sector following the outbreak of the coronavirus disease (COVID-19) pandemic from two points of view. First, it explores the factors that shape governments' willingness to support airlines. This is followed by a discussion on the various types of support that may be provided and how country-specific parameters influence the choice of measures. Second, it analyses the implications of government support in three dimensions relevant to air transport policy competition and liberalisation, airline ownership and control, and environmental sustainability. The analysis suggests that most governments give a high priority to maintaining air transport connectivity in order to protect economic activity and jobs, in aviation itself and in related sectors such as tourism. The trade-off between ensuring connectivity and maintaining competition after the COVID-19 pandemic is a challenge with several political and economic dimensions. The re-orientation of public policy in the aftermath of the pandemic may limit the relative importance of the policy priorities that shaped the evolution of the air transport sector before the crisis, especially those related to climate change and the environment.