Boeing issues warning on potential instrument malfunction after Indonesia crash
By TIMOTHY MCLAUGHLIN AND STANLEY WIDIANTO | Special to The Washington Post | Published: November 7, 2018
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 in a statement that 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 flight-control 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 on Wednesday evening in Jakarta, accident investigators showed reporters the AOA sensor that was removed from the aircraft on 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.
Ony Suryo Wibowo, another investigator, said that it was still too early to say definitively what caused the crash.
"We cannot conclude much this early in the investigation," he said. The full investigation could take up to 12 months, he added.
The Boeing 737 Max 8 jets are among the manufacturer's newest models, and have been snapped up by airliners 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 re-creation will be done at Boeing's facilities in Seattle and will replicate the flight's actual path and journey. Boeing also said that it continues to provide support and technical assistance to the Indonesian investigators and other government authorities.
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. On Wednesday morning, members of Indonesia's national search and rescue team used helicopters and boats as they looked for the cockpit voice recorder, more wreckage and bodies. Officials have recovered pieces of the plane, including the left engine and right landing gear, but have yet to locate the main fuselage.
A ship from the port city of Balikpapan on the island of Borneo with equipment to dig across the muddy seafloor in an effort to find the cockpit voice recorder would soon be dispatched to the crash scene, investigators said.
Even if the recorder was not found, investigators would eventually determine what was behind the accident, Nurcahyo said.
The Washington Post's Shibani Mahtani in Singapore and Ainur Rohmah in Jakarta contributed to reporting.