Captain Wolfgang Arminger (56) was the pilot-in-command. The flight departed at 10:59 CEDT, shortly after which it was found to be impossible to fully retract the landing gear, as indicated by both the red "gear unsafe" lamp and the yellow "gear door open" lamp. After a total of four retraction attempts, the gear was left in the fully extended condition where all lights indicated a valid condition with the doors trimmed for cruise airspeed. The flight continued towards Germany, as fuel must be burned before landing in any case. The crew had to cope with a heavier cockpit workload that was aggravated by the unavailability of the airline HF radio station for technical consultation, forcing the first officer to spend almost an hour establishing alternative communications with the airline through ACARS and Stockholm Radio. Using the Flight Management System (FMS), the crew estimated the aircraft's fuel consumption, and the captain in consultation with dispatch decided to shorten the flight and divert to Munich, where another A310 would be ready to take the passengers to their final destination. However, the captain ignored the fact that the FMS was not designed to take into account the extra drag produced by the extended landing gear. In fact, Munich was not within range, as eventually became clear from the unexpectedly rapid fall in fuel reserves. At about 12:00 CEDT, this led the captain to decide to divert to Vienna-Schwechat Airport.