The spillage caused "significant communication difficulty."
A plane was forced to land at Shannon Airport after coffee was accidentally spilled in the cockpit, according to an incident report.
The Condor aircraft was flying over the Atlantic earlier this year when it was diverted to the Irish airport following a spillage.
According to the Air Accidents Investigation Branch (AAIB), the coffee led to "significant communication difficulty."
It also caused smoke and an electrical burning smell inside of the cockpit.
No crew or passengers were injured during the diversion.
Sky News reports that the incident, which occurred on February 6, caused the Airbus A330 flight from Frankfurt, Germany to Cancun, Mexico to turn back and divert to Shannon.
The coffee, spilled by the plane's captain, had been placed on a tray table when it was knocked over.
Airbus rules recommend that crew use cupholders provided when drinking beverages in the cockpit, however the size of cups made it difficult for them to be grasped when in the holder.
Since the incident, Condor has encouraged its pilots to be careful when handling hot drinks in the cockpit.
They have also provided lids for all coffee cups on board.
