Wizz Air is looking at adding a sixth aircraft to its Skopje base from May of next year and has increased planned frequencies on a number of routes from the Macedonian capital as a result. The development is also a clear sign the airline plans to take part in the upcoming public call, to be issued by the Macedonian government, aimed at subsidising the launch of new routes from the country between 2023 and 2025. Wizz Air has won all three previous such tenders. The budget carrier, which has…