What a cockpit-block.

An airplane captain has been suspended for locking his female co-pilot out of the flight deck because she went to the bathroom during a 10-hour flight.

The Sri Lankan Airlines flight had been traveling from Sydney, Australia to Colombo, Sri Lanka, last month when the first officer decided to use the lavatory, leaving her male compatriot alone at the controls, News.com.au reported.

When the sky consigliere returned, she found herself unable to open the door to the flight deck.

As it turned out, the “petty” officer had locked her out because she had not arranged for someone to take her place during her bathroom break — a violation of “standard operating procedures.”

His self-imposed solitary confinement caused a tense standoff that was finally resolved after senior crewmembers persuaded the flyboy over the intercom to let his co-pilot back in (like a reverse hostage situation).

The plane, transporting 297 passengers, safely landed at its destination without any further incidents.

The pilot has since been grounded Sri Lankan Airlines is investigating the matter with Sri Lanka’s Civil Aviation Authority (CAA).

The carrier also released a statement addressing the captain’s bizarre lock-pit measure.

“The airline is fully cooperating with the relevant authorities, and the captain has been grounded pending the outcome of the investigation,” airline reps said, per Simple Flying. “Safety and compliance with all regulatory requirements remain Sri Lankan Airlines’ top priorities.”

While pilots can leave the cockpit midflight to use the lavatory, international aviation protocols mandate that two pilots be present on the flight deck at all times, Simple Flying reported.

If there is no third relief pilot, a flight attendant must stand in the control room until the first officer returns.

During long-haul flights, there are generally three to four pilots, ensuring that there’s always someone controlling the aircraft as others get adequate rest or use the bathroom.