US govt's accident investigation agency issues an urgent warning for Boeing, Airbus planes

The U.S. National Transportation Safety Board (NTSB), an independent U.S. government investigative agency responsible for civil transportation accident investigation, has issued an urgent safety alert concerning certain engines used in Boeing and Airbus aircraft, warning of a risk that smoke could fill the cockpit and passenger cabin during flight.

The warning applies specifically to CFM International’s LEAP-1B engines, which are used on Boeing 737 Max and some Airbus A320neo aircraft. The NTSB says a safety feature called the load reduction device—designed to limit vibrations if an engine is damaged—can accidentally interfere with the engine's oil system, allowing hot oil fumes to leak into the plane’s ventilation.

“Such a condition can allow smoke from hot oil to enter the ventilation system and ultimately the cockpit or passenger cabin,” the NTSB said.


The advisory follows a series of smoke-related incidents, including one on a Southwest Airlines Boeing 737 Max in December 2023, when the jet’s left engine ingested a bird shortly after takeoff from New Orleans. The cockpit filled with thick, “acrid white smoke,” forcing the crew to wear oxygen masks and return to the airport. A similar event was reported on another Southwest flight out of Havana earlier that year.

While no injuries were reported in either case, the NTSB is urging the Federal Aviation Administration (FAA) to require airlines to inform flight crews if their aircraft are equipped with the affected engines. Boeing has already updated its flight manuals to help pilots manage such scenarios.

The NTSB also called on aviation regulators in Europe and China to evaluate whether other variants of the CFM LEAP engine might face similar problems. In addition, the agency is recommending that both the FAA and the European Union Aviation Safety Agency (EASA) mandate new software modifications developed by CFM and Boeing to prevent future smoke incidents.

“We are aligned with the NTSB’s recommendations, and work is already underway in close partnership with our airframers,” a CFM spokesperson told The Independent.

The warning comes amid growing scrutiny of U.S. aviation safety, following several recent incidents—including a deadly plane crash in Philadelphia and a mid-air collision near Washington, D.C.—that have raised alarm across the airline industry.