BANGKOK -- Boeing faced new scrutiny on Tuesday over the crash of one of its planes into the sea off Indonesia last month, as airlines, pilots and regulators sought to determine whether the company had underplayed the complexity of a new emergency system suspected of having malfunctioned on the doomed jetliner.
Investigators have been focused on whether the plane, Lion Air Flight 610, crashed because the system, which is designed to pull the plane out of a dangerous stall, activated based on inaccurate data transmitted or processed from sensors on the fuselage.
The plane plunged nose-down into the sea, killing all 189 people on board. The precise cause or causes of the crash remain unclear.
Boeing has been selling the model that crashed, the new 737 Max 8, as requiring little additional pilot training for airlines that already use the previous version of the plane. The 737 Max 8 is in a competitive battle with an update of the Airbus A320, and minimizing the costs of upgrading to the new model is one of the keys to winning orders from airlines.
The pilots' union for American Airlines, which also flies the Max 8, said Tuesday that the emergency system in question had not been included by Boeing in the standard operating manual. In addition, the flight checklist -- which contains information for manually overriding the emergency system -- was incorrect, the union said.
The emergency system is intended to maneuver the plane out of a stall, when its nose is often angled too sharply upward. The system automatically pushes the nose down. If activated incorrectly, it could have sent the plane into its fatal dive, especially if the pilots were not properly trained on how to deal with such a situation.
Boeing has delivered 200 of the planes to airlines around the world, with many more in the pipeline. It is already in use in the United States by American Airlines and Southwest, and other customers include Air Canada, Norwegian Air and Icelandair.
Boeing said in a statement that it was assisting in investigations into the crash, but it did not directly address questions about why it did not do more to emphasize the changes in the anti-stall system.
"The investigation into Lion Air flight 610 is ongoing and Boeing continues to cooperate fully and provide technical assistance at the request and under the direction of government authorities investigating the accident," the company said.
The U.S. Federal Aviation Administration said Tuesday evening that it had received a letter from Boeing requesting permission to update the 737 Max 8's flight manual. The letter is not an unusual response after the agency issues airworthiness directives, and it is not known what specific changes Boeing was requesting.
The Wall Street Journal first reported about concerns that Boeing had not adequately informed airlines about the changes to its emergency system.
The question of whether cost pressures contributed to any decision by Boeing to fully brief airlines on how the new emergency system works and how pilots need to respond differently to it in case of a malfunction injected a new element into the investigation.
"We've just been informed that there's an entire new system on the Max," said Capt. Dennis Tajer, a 737 pilot and spokesman for the Allied Pilots Association, the union for pilots at American Airlines.
He said he was referring to what is known on the new version of the plane as the MCAS, or maneuver characteristics augmentation system. The previous system, and the one in the standard manual, goes by a different shorthand, EFS, for elevator feel shift.
The union is still studying the similarities and differences between the two systems "so that our pilots can be trained up and be able to recognize while they're actually flying the aircraft," Tajer said.
In addition, he said, the onboard checklist that pilots had been carrying gave what now appears to be incorrect instructions for pulling out of the emergency condition that apparently confronted the Lion Air pilots.
Boeing had told airlines that pilots qualified to fly the earlier version of the plane, the 737NG, would need to do just 16 hours of training on a computer to be ready to fly the new Max version.
American Airlines said in a statement that it had not had any similar problems with the 16 Max 8 jetliners it is currently flying, but that it had been unaware of the issues with the way the emergency anti-stall system works.
"The work with the FAA and Boeing is ongoing, and we will continue to keep pilots informed of any updates," the airline said.
Indonesian transportation officials have said repeatedly that the Max 8 manual being used in the country did not contain crucial information about the new anti-stall mechanism.
Soerjanto Tjahjono, the head of Indonesia's National Transportation Safety Committee, said Boeing's manual did not adequately describe how this automatic anti-stall system worked and what to do if it was triggered incorrectly.
Pilots would only have a few seconds to respond to this situation, aviation experts said, especially if a plane was flying at low altitude, as was the case with Lion Air flight, which plummeted into the Java Sea on Oct. 29.
"The manual has how to handle issues but not that specific combination," Soerjanto said. "I don't know why it was not in the manual. Maybe Boeing never thought that this kind of problem would occur."
A Section on 11/14/2018