FAA Examines Boeing 737 Smoke Risks After Bird Strike Incidents

(Bloomberg) — US aviation regulators are examining whether pilots of Boeing Co.’s 737 Max should take new precautions following two incidents in which planes were filled with smoke after large birds struck the engines. 

A small group of investigators at the Federal Aviation Administration has developed internal recommendations on how to address the issue, including potentially requiring pilots to shut down one or both air conditioning packs during takeoff that regulate airflow in the cockpit. The recommendations, seen by Bloomberg News, also urge the FAA to review all novel and unique features of the 737 Max to ensure that they are adequately communicated in pilot operating manuals. 

A representative for the FAA said Thursday that the agency is convening a Corrective Action Review Board “in the coming weeks,” and that the board’s work will include “thoroughly evaluating the internal FAA safety recommendations.” The National Transportation Safety Board said separately Thursday that it was gathering information about the bird-strike incidents but didn’t say whether it would conduct its own investigation. 

The mishaps involved Boeing Co. 737 Max aircraft flown by Southwest Airlines Co. and LEAP-1B engines made by CFM International, a joint venture of General Electric Co. and Safran SA. The FAA said it’s collaborating with Boeing, CFM and European aviation safety regulators to address the engine issue. 

The review board — which identifies and evaluates safety issues, develops corrective steps and can order changes at airlines or manufacturers — will “examine the data and develop a path forward,” the FAA said in a statement. “The FAA has determined this is not an immediate flight-safety issue.”

Following the incidents, Southwest said it notified pilots about the effects of the bird strikes and reiterated safety procedures for such incidents. The airline “continues to address this issue through its robust safety management system while working with the manufacturers and safety regulators to identify a permanent solution,” it said in a statement Thursday.

The system linked to the smoke incidents doesn’t appear in pilot training or operating materials, which “is very concerning,” the internal FAA group said, likening it to the flight control system tied to two fatal 737 Max crashes in 2018 and 2019. 

The incidents involved a Southwest flight from Havana to Fort Lauderdale, Florida, on March 5, 2023, in which at least one turkey vulture was sucked into the engine. In the second, a female bald eagle hit the engine of a New Orleans to Tampa flight on Dec. 20. Both incidents caused heavy fan blade damage, according to a CFM presentation seen by Bloomberg News. 

In both instances, damage to the fan blades activated a load reduction device in the LEAP-1B engines designed to reduce unbalanced dynamic loads in engine structures, followed by shutdowns. Engine oil sumps were also damaged in both cases, allowing oil to hit the high-temperature engine compressor, resulting in smoke and fumes that can be fed into the cockpit from the left engine and into the cabin from the right, based on a memo sent by Southwest to its pilots in February.   

“These engine failures occurred during a critical phase of flight and were further compounded by the immediate presence of smoke and fumes associated with the severe engine damage entering either the flight deck or the cabin through the air conditioning system,” the bulletin said. The note, along with a similar one from American Airlines Group Inc. to its pilots, also contained information from Boeing. 

“Load Reduction Devices have been widely used across the industry for more than 20 years and operated as designed,” a spokesperson for CFM said in a statement. “We are collaborating with the FAA, EASA and Boeing to determine if there are any learnings from recent events.” 

A spokesperson for Boeing said the planemaker is working with the authorities that are investigating the incidents. “We continue to follow regulatory processes to properly address potential issues and ensure the continued safety of the global fleet,” they said. 

–With assistance from Julie Johnsson.

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