to demand being lower than expected. In September 2015, it was announced that InterSky was still loss-making and the owner, German investor Intro Aviation, planned to sell the company entirely. All flights from Memmingen Airport and Zürich Airport as well as the Friedrichshafen-Düsseldorf route was terminated in immediate effect. Additionally, InterSky tries to find another usage for their two ATR72-600s whose purchase back in 2013 has been called a mistake. In October 2015, InterSky reported to be in advanced negotiations with a potential investor from Germany willing to pay 5 million Euros for the airline. Shortly after, the Austrian aviation authorities requested InterSky to provide information over their financial security by 5 November 2015. Otherwise their operational license could be revoked. On 4 November 2015, the aforementioned sale agreement fell through. In the same time, InterSky submitted the requested documents regarding their financial security to the Austrian authorities. Shortly after, the airline announced plans to go into administration while maintaining operations. However, on the evening of 5 November 2015, InterSky announced that they were forced to cease all operations immediately as the lessor of its fleet seized four of the airline's five aircraft - both ATR 72-600s and two Bombardier Dash 8 Q300s - over unpaid leasing charges on short notice. All four aircraft were returned to the lessor immediately, while the remaining one - which was owned by InterSky - operated the last flight from Zürich to Graz. Previously, a potential investor declined to financially support the plans to go into administration. On 6 November 2015, the airline announced it had files for insolvency. It has been reported that the airline accumulated around 5 million Euros of debt with several airports being amongst the creditors. Destinations InterSky operated scheduled and charter flights to the following destinations : Austria Graz - Graz Airport Salzburg - Salzburg Airport Croatia Pula - Pula Airport seasonal Zadar - Zadar Airport seasonal Germany Berlin - Berlin Tegel Airport Cologne/Bonn - Cologne Bonn Airport Düsseldorf - Düsseldorf Airport Friedrichshafen - Friedrichshafen Airport base Hamburg - Hamburg Airport Memmingen - Memmingen Airport focus city Munich - Munich Airport seasonal Greece Naxos - Naxos Island National Airport seasonal charter Italy Elba - Marina di Campo Airport seasonal Spain Menorca - Menorca Airport seasonal Switzerland Altenrhein - St. Gallen–Altenrhein Airport seasonal Zürich - Zürich Airport United Kingdom Guernsey - Guernsey Airport seasonal charter Jersey - Jersey Airport seasonal