AeroMéxico flight 3351 had to return and make an emergency landing at Mexico City International Airport, Mexico, on December 23.
The plane took off for Cancún, Mexico, but had to return shortly afterwards after a portion of right engine cover became detached.
The plane landed uneventfully. No injuries were reported.
Mahan Airlines flight W5-1095 had to make an emergency landing at Mehrabad International Airport in Tehran, Iran, on October 15.
The Boieng 747-300 took off for Bandar Abbas, Iran, but had to return immediately afterwards after a part of the right hand engine detached mid-air.
The plane landed safely. All 426 people aboard remained unhurt.
Authorities said the engine part substantially damaged the plane’s fuselage.
The airline arranged replacement planes for the passengers.