The European Aviation Safety Agency (EASA) has together with the European Commission decided to introduce new Flight Time Limitations (FTL) that came into force February 2016. How these new FTL will affect sleep, sleepiness and fatigue levels among Swedish commercial airline pilots was the major aim of the current project, named CHARLES. In the first part of the project, questionnaire data were collected from 598 Swedish pilots (61% response rate) with questions about sleep, sleepiness, fatigue, health, working hours, and the work environment. The second part included working time analyses of a month (autumn 2015) that was subject to the former FTL (Subpart Q and LFS 2008:33). The last part of the project consisted of a field study to obtain objective data of the situation under the current FTL. Although the questionnaire results showed that job satisfaction in general was high, certain working time related phenomena were considered problematic, most notably alternating early and late flight duty periods and the fact that rosters were received less than 14 days in advance. For long haul operations, short layovers were mentioned as the main problem. A vast majority of pilots reported to have made errors due to fatigue since the introduction of the new FTL and that they should have reported themselves unfit for flight at least once. Despite a considerable prevalence of disturbed sleep and insufficient recuperation whilst on leave, self-reported health was good. Working time analysis of the older FTL revealed that long-haul and regional operations were associated with the highest working time at a critical level of sleepiness. Field study results showed no signs of systematic insufficient sleep, although slightly longer (recovery) sleep was observed during days off. Hotel sleep was found to be shorter and worse than sleep at home. Sleepiness on the flight deck tended to culminate towards the end of any given working period, with a further considerable rise during the 5th sector (if any). About one fifth of all working days were associated with sleepiness up to a level that countermeasures felt appropriate and napping and coffee intake were among the most popular ones to take. Despite the fact that problems, like too many rotating shift schedules, occur in Swedish aviation, the overall picture does not differ very much from other occupational groups where shift work occurs. Certain working time arrangements do, however, leave room for optimization, and airliners should therefore consider taking actions such as having schedules that improve the possibilities for rest and recuperation in between working shifts rather than rotating between early and late check-ins and to find ways of giving pilots more influence on their own working schedules. Minimizing the number of early check-ins for evening types and late check-ins for morning types would be a good example.