On 26th November 2017 "Air Serbia" aircraft ATR 72-202 registration YU-ALO flying from Sofia to Belgrade with 36 passengers on board and 4 crew members took off from Sofia Airport. During the initial climb, at a height between 8000 and 10000 ft, the crew heard a loud clattering noise and felt vibrations as a result the crew decided to return and land at Sofia Airport. The aircraft landed safely at 16:21. After landing, it was found that a panel from the central part of the wing to fuselage fairing was missing. There were no injuries to the passengers and the crew