NTSB recommends Modifications to LEAP-1B engines

The National Transportation Safety Board issued an urgent safety recommendation Wednesday to address the possibility of smoke entering the cockpit or cabin of airplanes equipped with CFM International LEAP-1B engines and issued additional recommendations to evaluate the potential for the same issue with LEAP-1A and -1C engines. CFM LEAP engines are used on variants of Airbus (EADSY) A320neo and Boeing (BA) 737 Max narrow-body passenger jets. 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. Such a condition can allow smoke from hot oil to enter the ventilation system and ultimately the cockpit or passenger cabin. The recommendations stem from the NTSB’s investigation into a December 2023 incident in which smoke entered the airplane after a bird was ingested into the left engine of a Southwest (LUV) Airlines Boeing 737-8 shortly after departing New Orleans, Louisiana. 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. 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 airplanes 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 asking the agency to ensure that operators inform flight crews of airplanes 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 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. The CFM International LEAP is a high-bypass turbofan engine produced by CFM International, a 50-50 joint venture between the American GE Aerospace (GE) and the French Safran Aircraft Engines (SAFRY).