NTSB bird strike investigation sees CFM and Boeing collaborate on software design update
December 20, 2024
As part of an ongoing investigation into a bird strike incident involving a Southwest Airlines B-737 on 20 December 2023, a recently released preliminary report from the National Transportation Safety Board (NTSB) has confirmed that CFM International, in collaboration with Boeing, is working on a software design update of its LEAP-1B engine.
The Southwest Airlines flight at the centre of the investigation had been carrying 139 occupants when the bird strike occurred as the aircraft departed from Louis Armstrong International Airport (MSY) in Louisiana. According to NTSB’s report the “bird ingestion occurred in the left engine during the initial climb out.”
Although the aircraft returned to MSY with no injuries reported, the pilot did report violent shaking with a distinct loss of thrust in the left (No. 1) engine as a result of the strike. Smoke quickly filled the flight deck forcing the pilots to return to their departure airport where airport rescue and firefighting teams were requested on be on standby.
The 737-Max aircraft was equipped with two CFM International LEAP-1B engines, which incorporate a load reduction device (LRD) designed to minimise aircraft and engine damage during a significant fan imbalance.
NTSB’s report revealed that the activation of the LRD resulted in oil being ingested into the air conditioning system, which resulted in smoke quickly filling the cabin.
One of two bird strike incidents
The December incident followed a separate bird strike event in March 2023 also involving a Southwest Airlines 737 MAX 8 aircraft, which had to initiate an emergency landing at its origin airport (Havana Jose Marti International Airport) when “vapour fog” entered the passenger cabin.
NTSB is working alongside the Federal Aviation Administration (FAA), Boeing, CFM, Southwest Airlines and the Southwest Airlines Pilots Association on the investigation, which is ongoing.
In a statement in November, the FAA, which alongside the European Union Aviation Safety Agency (EASA) had jointly certified the CFM International LEAP-1B engine in 2016, revealed it was already addressing CFM’s LEAP-1B engine issue through its standard operational safety process. It had determined the issue was “not an immediate flight safety issue”, but that it would continue working with the authorities investigating the issue.
Following the bird strike in New Orleans, Boeing released a Flight Crew Operations manual (FCOM) bulletin and made updates to the FCOM and quick reference handbook (QRH).
