A pilot locked a woman co-pilot out of the cockpit of a Sydney-Colombo SriLankan Airlines flight when she took a mid-air toilet break.

The incident was reported aboard a 10-hour-long flight, when the pilot took a break without arranging for her substitute in the cockpit, as per standard operating procedures. This led to a a stand-off between the two pilots.

The male pilot locked the woman pilot out when she went to use the restroom. To remedy the situation, a cabin crew member used a communication link to the cockpit to urge the captain to let the co-pilot back in.

Sri Lanka’s Civil Aviation Authority is investigating the incident. The airline, meanwhile, said it is fully cooperating with the probe and the male pilot has been derostered till the investigation concludes.

With safety concerns in mind, several airlines and aviation authorities mandate the presence of at least two crew members in the cockpit at all times during a flight.