TOKYO >> A Japanese airline says one of its jets nose-dived and rolled almost upside down earlier this month because the co-pilot hit the wrong controls while trying to open the cockpit door so the captain could return from a restroom break.

Two flight attendants were slightly hurt and four passengers got airsick when the All Nippon Airways Boeing 737-700 with 117 people aboard descended sharply, veered off course and went belly up over the Pacific on its way from southern Japan to Tokyo on Sept 6.

ANA said today that the co-pilot is believed to have mistakenly hit the rudder controls instead of the door lock to allow the pilot back in the cockpit. It said the crew managed to stabilize the plane after the co-pilot’s error and land it safely.

Japan’s Transport Safety Board is investigating.