Federal regulators have issued a rare, urgent warning over the risk of Boeing 737 MAX engines malfunctioning and letting smoke into an airplane cabin or cockpit.
Damage to the engine’s oil system can cause smoke from hot oil to enter the airplane ventilation system and fill the cabin or cockpit – presenting an extreme danger of incapacitating the pilots, the National Transportation Safety Board wrote in a report released Wednesday.
The recommendations were inspired by two incidents on Southwest Airlines flights, when CFM International LEAP-1B engines malfunctioned after bird strikes and poured smoke into the cabins.
In December 2023, a Boeing 737-8 filled with “acrid white smoke” shortly after takeoff from New Orleans, La. It was so thick that the captain struggled to see the instrument panel in the cockpit, the NTSB said.
An engine on another flight in March 2023 was similarly damaged by a bird strike, allowing fog to funnel into the passenger cabin shortly after departing Havana, Cuba.
Both flights required emergency landings, and there were no injuries, the safety agency said.
The NTSB is recommending modifications to the engines, which are used on Boeing 737 MAX planes and Airbus A32 jets.
In an urgent notice, it is asking the Federal Aviation Administration to evaluate whether LEAP-1A and LEAP-1C engines have the potential for the same issue.
The NTSB also expressed concern that flight crews are unaware of the potential smoke hazard and won’t know how to take action. The agency said it had urged the FAA to require operators like Boeing to alert crews of the smoke risk.
Boeing has already revised its flight manuals for pilots detailing what steps to take to prevent smoke from entering the cockpit or cabin, the NTSB said.
“CFM International and Boeing have been working on a software design update. We support the NTSB’s recommendation,” Boeing told The Post in a statement.
GE Aerospace, which owns CFM International, told The Post it is also aligned with the NTSB’s recommendations and “the work is already underway.”
