Aerotrans Cargo flight ATG-4428 had to return and make an emergency landing at Frankfurt-Hahn Airport, Germany, on February 15th.
The Boeing 747-400 plane took off for Baku, Azerbaijan, but had to turn back after an unidentified loud bang was heard on-board.
The plane landed back safely. Everyone aboard remained unharmed.

United Airlines flight UA-135 had to return and make an emergency landing in Zurich, Switzerland, on May 20th.
Flybondi flight FO-2710 made an emergency landing in Cordoba, Argentina, on January 22nd.
Copa Airlines flight CM-156 had to divert and make an emergency landing in Mexico City, Mexico, on October 18th.