Lifting the lid on what caused an emergency landing on Air Condor's Cancun flight

Most of the coffee ended up on the pilot's lap, but soon came the smell of burnt electrics. Photo / Getty Images

The Condor flight from Frankfurt, Germany to Cancun, Mexico on Feb. 6 was nothing to write a safety report about. Until the coffee was served.

According to a report published Thursday from a branch of Britain's Department for Transport, the mishap that followed disrupted the plane's communications systems, caused a burning smell in the cockpit, prompted pilots to use oxygen and forced the flight with 326 passengers aboard to land in Shannon, Ireland. It also necessitated a new coffee-service policy.

For whatever reason, namely the size of the cup vs. the size of the cup holder, the pilot on flight DE2116 put his cup of coffee, sans lid, on a tray table.

"In the [Airbus] A330, flight crew were provided with a table in front of them, and it was a natural place to put a drink momentarily," the UK's latest Air Accidents Investigation Branch Bulletin says. "However, objects here are vulnerable to being knocked over because it is a fold-out table in a small space." The report also notes that Airbus "highly recommends" that every item in the cockpit go in its assigned place. "Cups in the cup holders," the bulletin quotes an Airbus manual as saying.

Around 4:20 p.m., according to the bulletin, "the cup was knocked over" while the plane was flying over the Atlantic. Most of the coffee ended up on the pilot's lap, but a small amount spilled onto his audio control panel on the center console. Despite efforts to dry the liquid quickly, the audio unit - used to make announcements to the plane and for VHF transmissions - malfunctioned right away. By 5 p.m., it became "very hot and failed," creating an electrical burning smell in the cockpit.

Shortly after, around 5:20 p.m., the co-pilot's audio control panel had heated up enough that a button melted. It too failed, and smoke could be seen coming from the first panel. At that point, the bulletin said, the pilot decided to turn the plane around and land in Shannon. Because of the audio control failures, the pilot could not hear or transmit messages and had to rely on the co-pilot's speaker to hear any transmissions.

"During the diversion, the flight crew alternately used supplementary oxygen, with one pilot on oxygen at all times," the report said.

At the time, local media reported that the flight made an emergency landing at 7:13 p.m. in Shannon, with five people taken to the hospital for smoke inhalation. The Department for Transport report does not say which airline was involved in the incident, but Condor - which is part of British travel company Thomas Cook Group - confirmed that it operated the flight.

In a statement Thursday, the airline said the diversion was a "precautionary measure due to a minor amount of smoke in the cockpit after a liquid spillage." The flight continued by way of Manchester, because of the crew's legal operating hours, after the plane was inspected and repaired.

Both audio units were taken out and stripped down as part of an investigation. The vendor, according to the British bulletin, said the initial panel failed because of an electrical short caused by liquid contamination. It was not clear what caused the second panel to fail. Condor said in its statement that the airline "comprehensively investigated" the situation and has since gone over the procedures for liquid in the cockpit.

"Our crews were reminded of a careful handling as well as to use appropriate containers for their water or coffee," the statement says.

In the "safety actions" section of its report, the British bulletin said the airline will make sure lids are provided for cups on all routes - and will supply cups that fit in the plane's cup holders.