Is it permissible to work for a company that supplies aircraft with fuel, knowing that these aircraft may carry unveiled women or alcohol, especially given the difficulty of finding other work?

Working in the refueling of civilian transport planes is permissible, because its purpose is lawful, which is the transportation of passengers. The means take the ruling of the objective. It has no connection to the Sharia violations present on planes, such as the immodest display of flight attendants or the serving of alcoholic beverages.