German airline Condor was flying from Frankfurt to Cancun on February 6th when the Airbus A330 declared an emergency about 880 nautical miles west of Shannon, Ireland.

There was reported smoke in the cockpit. The “flight crew donned their oxygen masks” and declared mayday via ACARS, the digital short message system, because communications were hobbled. After dumping fuel (something not all Airbus A330s can – or need – to do) flight DE2116 landed safely at Shannon two hours after turning around.

Four of the plane’s cabin crew and one passenger were hospitalized for smoke inhalation, though initially there was “no trace of fire, heat or smoke.”

The next day the airline determined that the smoke had come from a liquid which had spilled in the cockpit. After repairs in Shannon the plane left for Manchester, England the next day. They picked up a new crew and departed back for Cancun.

So what happened? A coffee spill.

• There’s a coffee cup holder in the cockpit
  
• But Condor’s coffee cups don’t fit well in it, the cups are difficult to get back out, so pilots don’t use it
  
• And coffee, which was served to the captain without a lid, spilled.

Condor flight DE-2116 at @ShannonAirport this evening after turning around over the Atlantic and diverting. Crew reported smoke in the cockpit. Met on arrival by airport fire crews, Clare County Fire Rescue Service (Shannon & Ennis), National Ambulance Service and An Garda. pic.twitter.com/5G8NCu5LDE

— Pat Flynn (@patsyflynn) February 6, 2019

Coffee wound up on the captain’s audio control panel, taking it out. Then after 20 minutes the first officer’s panel failed too.

The UK Air Accidents Investigation Branch says that, while Airbus recommends using the cup-holder, the size of cups used by the carrier on the route made lifting them from the holder difficult.

“This incompatibility generally discouraged use of the cup holder, despite the policy,” it states, adding that the crew naturally tended to place cups on the fold-out table in front of them – making them “vulnerable” to being knocked over.

Condor now provides lids for beverages in the cockpit and “has sought to obtain” cups that fit better in the cup holders so that crew will use those.

Four year’s ago the President of Serbia’s plane – headed to a meeting at the Vatican – was nearly downed by a coffee spill. The aircraft dove and briefly shut down one of its engines.