NTSB raises serious concerns over LEAP-1B engines on Boeing 737 MAX jets
The National Transportation Safety Board (NTSB) has raised serious concerns over CFM International LEAP-1B engines used to power Boeing 737 MAXs.
On June 18, 2025, the NTSB issued an urgent safety recommendation over fears that smoke could enter the cockpit or cabin of aircraft equipped with LEAP-1B engines.
The safety agency also issued additional recommendations to evaluate the potential for the same issue with LEAP-1A and -1C engines.
LEAP-1B engines are used exclusively by Boeing 737 MAX jets while LEAP-1A and -1C engines are used on some variants of the A320neo family aircraft and COMAC C919s.
In a statement, the NTSB said: “The NTSB found that the engine load reduction device, or LRD, a safety feature designed to reduce the severity of vibrations transmitted from a damaged engine to the airframe, can result in damage to the engine oil system.”
It added: “Such a condition can allow smoke from hot oil to enter the ventilation system and ultimately the cockpit or passenger cabin.”
Previous incidents
The NTSB cited an incident in December 2023, where smoke entered the plane after a bird was ingested into the left engine of a Southwest Airlines Boeing 737-8 shortly after takeoff.
“The flight deck filled with what the crew described as “acrid white smoke” so thick that the captain had difficulty seeing the instrument panel. The crew donned masks, were able to clear the smoke, and landed the airplane back in New Orleans. None of the crew or passengers were injured,” the NTSB said.
A similar engine damage event occurred in March 2023 on another Southwest flight when vapor fog filled the passenger cabin after birds were ingested into the right engine shortly after departing Havana, Cuba.
The flight crew declared an emergency and returned to the departure airport without further incident.
Concerned that flight crews operating these planes may not be fully aware of the potential hazard of an LRD smoke-related event along with the appropriate mitigation actions, the NTSB issued an urgent safety recommendation to the Federal Aviation Administration (FAA).
The NTSB asked the agency to ensure that operators inform flight crews of planes equipped with the affected engines.
Boeing has revised flight manuals for pilots detailing the steps to take to prevent smoke from entering the cockpit or cabin following an LRD activation.
In safety recommendations issued to the FAA, the European Union Aviation Safety Agency (EASA) and the Civil Aviation Administration of China, the NTSB asked the aviation regulators to determine if other variants of the CFM LEAP engine are also susceptible to smoke in the cabin or cockpit when an LRD activates.
The NTSB also asked the FAA and EASA to require all operators of the affected engines to incorporate software modifications developed by CFM and Boeing.
RELATED
Air India to cut 15% of long-haul widebody operations until mid-July 2025
The post NTSB raises serious concerns over LEAP-1B engines on Boeing 737 MAX jets appeared first on AeroTime.
The National Transportation Safety Board (NTSB) has raised serious concerns over CFM International LEAP-1B engines used to power…
The post NTSB raises serious concerns over LEAP-1B engines on Boeing 737 MAX jets appeared first on AeroTime.
