A Lufthansa plane carrying nearly 200 passengers was left without an active pilot for nearly 10 minutes after the first officer lost consciousness in the cockpit—while the captain was using the bathroom, a new investigation has found.

The mid-air incident occurred in February last year aboard an Airbus A321 en route from Frankfurt, Germany, to Seville, Spain. The aircraft was carrying 199 passengers and six crew members, according to a report released this week by Spanish aviation investigators.

According to the report, the 43-year-old captain (whose name was not disclosed) left the cockpit with about 30 minutes remaining in the flight to use the lavatory. He noted that the 38-year-old first officer appeared “able and alert” at the time.

However, when the captain returned approximately eight minutes later, he was unable to access the cockpit despite entering the security access code five times. When an intercom call to the flight deck went unanswered, the captain used an emergency access code.

Shortly before the emergency code timer expired, the co-pilot manually opened the flight deck door from the inside.

“As the co-pilot was pale, sweating, and moving strangely, the captain called for assistance from the cabin crew,” the report stated. The crew, along with a doctor who happened to be on board, provided first aid and diagnosed the first officer with a possible heart condition.

The first officer later told authorities he was unaware of how long he had been unconscious. “He remembered flying over Zaragoza and, the next thing he knew, he was being attended to by the cabin crew and a doctor,” the report said. Investigators noted that the loss of consciousness was so sudden that the co-pilot was unable to alert the rest of the crew.

The aircraft remained in stable flight during the incident, thanks to the autopilot system. However, investigators said the cockpit voice recorder captured “strange noises” consistent with a sudden medical emergency.

Once back in control, the captain decided to divert the flight to Madrid, the nearest suitable airport. The first officer was taken to a hospital, where doctors determined that his sudden and severe incapacitation was the result of a seizure disorder linked to an underlying neurological condition.

His medical certification was suspended as a precautionary measure.

Lufthansa has not immediately responded to inquiries about the incident. A spokesperson for the airline told German news agency dpa that Lufthansa was aware of the report and had conducted its own internal investigation through its flight safety department, though the findings were not disclosed. (The New York Post)