Boeing issues warning after Lion Air crash
False sensor readings might be a factor in jet’s final moments
JAKARTA, Indonesia — Airplane manufacturer Boeing said Wednesday that it has issued a bulletin to airlines worldwide warning of erroneous readings from flight-control software on its planes, after an almost-new Lion Air jetliner crashed into the sea soon after takeoff, killing the 189 people on board.
Boeing, which is assisting in an investigation into what went wrong in the Oct. 29 crash of one of its new 737 Max 8 jets, said it issued a bulletin Tuesday as “part of its usual process.”
The bulletin informed airline operators on what to do if they receive false readings from flightcontrol software that measures the angle of the plane and alerted flight crews of the procedure they have to follow.
The bulletin from Boeing was the first indication that an error with the aircraft’s systems may have caused problems for the Lion Air flight, which took off from Jakarta. Instead of a smooth takeoff, the plane’s altitude fluctuated dramatically, and the plane increased in speed before nose-diving into the Java Sea 13 minutes later.
Indonesian investigators have recovered the plane’s flight data recorder, which showed that the plane’s airspeed indicator malfunctioned on its last four flights.
“The Indonesian National Transportation Safety Committee has indicated that Lion Air Flight 610 experienced erroneous input from one of its AOA (Angle of Attack) sensors,” said Boeing in the statement. A misreading in the sensor can cause the plane to dive suddenly.
Indonesian investigators said Wednesday that an AOA sensor on the jet was replaced the day before the doomed flight, on Oct. 28, when a pilot flying the same aircraft on a different route, from Bali to Jakarta, reported problems with it. The pilot on the crashed Lion Air flight had asked shortly after takeoff to return to the airport in Jakarta, but lost contact with air traffic controllers afterward.
At a news conference Wednesday in Jakarta, accident investigators showed reporters the AOA sensor that was removed from the aircraft Oct. 28. The small black cylinder with a fin that protrudes from the side of the aircraft near the cockpit was wrapped in a clear plastic bag.
Indonesian authorities would provide Boeing with information from the pilot who flew with the problematic sensor so that could be shared with other airlines in case they faced similar difficulties, Nurcahyo Utomo, an accident investigator with the National Transportation Safety Committee, said.
The Boeing 737 Max 8 jets are among the manufacturer’s newest models, and have been snapped up by airlines in booming aviation markets, including Indonesia and India. More than 200 of such planes are in service around the world, billed as the most advanced of the popular 737 jets.
The two Indonesian airlines that fly the Boeing 737 Max 8 planes, national carrier Garuda Airlines and Lion Air, which operates 10 of these planes, both declined to comment on the bulletin. Indonesian officials say that all 11 such aircraft have been tested for airworthiness and have been declared safe to fly.
On Wednesday, the Indonesian transportation safety committee said it would re-create the flight to see what role the possibly malfunctioning sensor may have played in the crash. The recreation will be done at Boeing’s facilities in Seattle and will replicate the flight’s path and journey.
Experts have been puzzled at what could have caused the almost-new jet to go down in clear skies, unlike other major airplane disasters in which weather or older jets were major factors. The data from the flight recorder and Boeing’s statement have provided the first clues, but rescuers continue to search for the device that records voices in the plane’s cockpit. That recorder is expected to provide a fuller picture to investigators of the Lion Air flight’s final moments.
Search operations continue in the Java Sea off the coast of Jakarta.