Passengers aboard a Boeing Co. 737 in Japan caught a scare earlier this month when a mistake by the co-pilot sent the jet plunging toward the earth.

All Nippon Airways revealed this week that the co-pilot on the flight hit a wrong knob while trying to open the cockpit door so the captain could return from a restroom break. The co-pilot instead hit the rudder control, which sent the plane into a roll.

The plane nearly flew belly up as a result of the error.

A official from Japan's transportation safety board told TMCnet that the centrifugal force exerted on the plane may have lessened the impact of the maneuver on the passengers.

A photo posted to tech blog Gizmodo on Wednesday purports to show the rudder and cabin door lock knobs, which look similar and are relatively near each other.

The jet landed safely and no one was seriously hurt.