Boeing Co. BA -3.33% withheld information about potential hazards associated with a new flight-control feature suspected of playing a role in last months fatal Lion Air jet crash, according to safety experts involved in the investigation, as well as midlevel FAA officials and airline pilots.
The automated stall-prevention system on Boeing 737 MAX 8 and MAX 9 modelsintended to help cockpit crews avoid mistakenly raising a planes nose dangerously highunder unusual conditions can push it down unexpectedly and so strongly that flight crews cant pull it back up. Such a scenario, Boeing told airlines in a world-wide safety bulletin roughly a week after the accident, can result in a steep dive or crasheven if pilots are manually flying the jetliner and dont expect flight-control computers to kick in.
That warning came as a surprise to many pilots who fly the latest models for U.S carriers. Safety experts involved in and tracking the investigation said that at U.S. carriers, neither airline managers nor pilots had been told such a system had been added to the latest 737 variantand therefore aviators typically werent prepared to cope with the possible risks.
Its pretty asinine for them to put a system on an airplane and not tell the pilots who are operating the airplane, especially when it deals with flight controls, said Capt. Mike Michaelis, chairman of the safety committee for the Allied Pilots Association, which represents about 15,000 American Airlines pilots. Why werent they trained on it?
One Federal Aviation Administration manager familiar with the details said the new flight-control systems werent highlighted in any training materials or during lengthy discussions between carriers and regulators about phasing in the latest 737 derivatives.
Boeing declined to immediately answer specific questions Monday. We are taking every measure to fully understand all...