UPDATE: The serious incident on the Air Nippon flight appears to have been caused by the co-pilot flipping the wrong switch to unlock the cockpit door to allow the aircraft captain to return after he had used the bathroom, according to the Japan Transport Safety Board. The board said the co-pilot had accidently moved a rudder switch located near the cockpit door lock, causing the plane to dive.
Two female crew members on a flight from Naha to Haneda suffered whiplash after their plane plummeted about 1,900 meters (6,230 feet) in 30 seconds when the pilot left the cockpit to use the bathroom, All Nippon Airways (ANA) said Sept. 7.
No passengers were injured, but there is a high likelihood of pilot error for the greater than normal fall.
Normally when problems arise, pilots may manually lower altitude, but at those times it is usually about a maximum of 1,500 meters (4,921 feet) per minute and the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) said the plane’s fall was too quick.
MLIT has designated the case as a “serious incident” and it is being investigated by the Japan Transport Safety Board.
ANA and MLIT said the incident occurred Sept. 6 on a flight of Air Nippon (ANK), a member of the ANA Group. The plane was on automatic pilot and flying about 12,500 meters (41,000 feet) about 40 kilometers (25 miles) south of Hamamatsu, Shizuoka prefecture, when the captain went on the toilet break. The plane titled to the left and lost altitude faster than it should have. The co-pilot steadied the plane.