We have witnessed dual aircraft crashes in under five months. One of them being the crash of Ethiopian Airlines Flight 302 and the other being the Lion Air Flight 610. Both times, a random computer control failure has led to the crash of a state-of-the-art aircraft. The prospect of such crashes is so fearful that a majority of the countries have banned the Boeing 737 Max 8 and Max 9. The ban will be lifted once the problem has been sorted out. These two crashes are not the only time that an automation failure has caused a plane to plummet. We have put together a list of some of the mishaps where the malfunction in plane automation software has put lives at risk.
October 2008
The Qantas Flight 72 was traveling from Singapore to Perth, Australia at 37,000 when all of a sudden the flight deck was taken aback by the sound of klaxons and flashing lights. The pilots were confused; horizon remained level outside the window and that the plane was flying quite normally. Then, all of a sudden, the plane’s nose jerked downward. The sudden jolt caused the passengers that were standing in the gallery to crash into the ceiling. Within two seconds, the plane had dived a distance of 150 feet.
The pilot soon regained control and brought the plane back to the cruising altitude while heading for an emergency landing. The plane dived again, without any warning, this time 400 feet and the passengers and crew were sent flying around the cabin. It eventually made an emergency landing at Exmouth, Australia. Thirty-nine passengers were rushed to the hospital, and 14 were medevacked to Perth with spinal injuries, lacerations, and broken bones.
The investigation revealed that a malfunction had taken place in the plane’s Air Data Inertial Reference Unit or ADIRU. This piece of equipment is used for ascertaining where the plane is and how it is moving.
May 2011
This incident involved a Dassault Falcon 7X business jet. The jet was descending through 13,000 on its way to Sultan Abdul Aziz Shah Airport located near Kuala Lumpur, Malaysia. It was then that it began to pitch upward steeply. Airspeed loss began, and the plane was nearing a stall that would have sent it back to Earth for a crash. The co-pilot was French-speaking and realized that he wouldn’t be able to convey the situation quick enough to the English-speaking captain. He executed a maneuver that he had learned in the military; he guided the plane into a steep bank thus causing the nose to turn sideways bringing it back towards the horizon. After a whole 120 seconds of erratic behavior, the rudder returned to neutral on its own. During these two minutes, the plane experienced loads of up to 4.6g.
The plane landed safely; however, the Falcon 7Xs were grounded all over the world. The problem was traced down to a bad solder joint that was causing the control unit to broadcast wrong signals.
November 2014
It was during the climb toward 31,000 feet after taking off from Bilbao, Spain when the co-pilot of a Lufthansa Airbus A321 realized that the autopilot was acting bizarrely. Upon turning it off, the nose of the Airbus dropped, and it dived. Within 45 seconds, the plane was descending at a speed of 4,000 feet per minute. However, with the help of the captain, the co-pilot was able to bring the plane to level off at 27,000 feet by pulling back on the stick.
The flight crew conferred with the technicians on the ground and switched off one of the ADIRUs. This removed the tendency of the plane to dive. The plane landed safely after continuing on its original route. Further investigations revealed that the two of the plane’s angle-of-attack sensors had frozen in place and were feeding bad data.
January 2016
West Air Sweden Flight 294, a Canadair CRK-200 cargo jet, slammed into a snow-covered tundra at 508 knots after an alarm klaxon rang. The jet was on its way to Tromso, Norway. When the alarm went off, the autopilot disengaged. The captain’s flight display was telling him that the nose was drifting too high thus putting the jet at risk for a stall.
The flight director, a display that is located on the instrument panel and provides control advice to pilots, told the pilots that they had to put the nose down. During training, pilots are specifically taught to trust their instrument when they don’t have any visual references. The captain obeyed the command of the flight director and pushed the plane forward. The push was aggressive, and the flight director’s call was faulty; the plane entered a negative-g dive causing the flight crew to hang in their straps.
The plane was in a steep dive when a fault in the ADIRU caused the flight computer to determine that the plane was pitched too high. This lead to the flight director suggesting the wrong command. The plane surpassed its maximum operating speed quickly and after 80 seconds of the bug popping up; it had slammed into the snow-covered tundra at a speed of 508 knots.
