Japanese aviation officials say analysis of a recent mishap shows an airliner plunged almost two kilometers in 30 seconds and turned almost upside down before the pilots recovered control.

Pilots on the trans-Pacific All Nippon Airways flight managed to land safely in Tokyo on September 6. Officials said Wednesday that two crew members were slightly injured and four passengers reported air sickness.

Air safety officials say the mishap occurred when the co-pilot hit a rudder control instead of the door lock when the pilot returned from a toilet break. The flight recorder shows the Boeing 737 banked right slightly, turned left, circled sharply and turned almost upside down. The plane descended 1,900 meters in half a minute.

Officials say that because it was dark outside, many of the 112 passengers did not realize what had happened.