Urgent Safety Bulletin Issued Over Boeing 737 Max Jets

The National Transportation Safety Board (NTSB) has issued an urgent safety bulletin concerning engines in some Boeing 737 Max jets. The alert highlights the risk of smoke entering the cockpit or cabin due to a flaw in the CFM International LEAP-1B engines. This issue arises from a safety feature called the load reduction device, which can inadvertently damage the engine's oil system after a bird strike, leading to smoke formation from hot oil entering the ventilation system.

The NTSB's investigation was prompted by two incidents involving Southwest Airlines flights in 2023. In one case, a plane departing from New Orleans experienced a bird strike, causing "acrid white smoke" to fill the cockpit, making it difficult for the captain to see the instrument panel. Another similar incident occurred in Havana, Cuba, resulting in smoke filling the passenger cabin. Fortunately, both flights landed safely without injuries.

The NTSB has recommended evaluating the potential for similar issues with CFM’s LEAP-1A and LEAP-1C engines, used in some Airbus A320neo and C919 jets. The Federal Aviation Administration (FAA) and Boeing have agreed with the NTSB's recommendations and have already warned airlines and pilots about the problem. Boeing and CFM are working on a software design update to address the issue. The FAA has advised operators to evaluate their procedures and crew training, ensuring they address this potential issue.

The NTSB has also issued recommendations to the FAA, the European Union Aviation Safety Agency, and the Civil Aviation Administration of China to assess the susceptibility of other CFM LEAP engine variants to similar smoke-related events. The NTSB's full investigation report is available online.