The United States Department of Transportation’s Office of Inspector General (OIG) has initiated an audit concerning the Federal Aviation Administration (FAA) following two cabin air quality events in 2023 involving Southwest Airlines Boeing 737 MAX 8 aircraft. The FAA’s Corrective Action Review Board (CARB) had decided not to recommend immediate safety actions after these incidents, which were caused by bird strikes affecting the CFM International LEAP-1B engines.
A memorandum from the OIG on April 16 announced that it will review the FAA’s actions with respect to load reduction devices (LRD) activating during bird strikes. These devices are integral to Boeing 737 MAX aircraft engines, and their activation during such events can result in toxic smoke and fumes entering the aircraft. The audit aims to evaluate the agency’s response to these risks and will encompass visits to FAA offices involved in the decision-making on events involving LRDs.
In a November 2024 communication, the FAA conveyed to Simple Flying, “the CARB determined the issue does not warrant immediate action, and the FAA will follow its standard rulemaking process to address it. The FAA will issue a Continued Airworthiness Notification to the International Community (CANIC) about new information Boeing provided to operators of aircraft with LEAP-1B engines. The new information contains enhanced instructions that direct flight crews more quickly to the appropriate actions when they experience abnormal engine indications.”
The OIG specified that engine damage from bird strikes in March and December 2023 introduced smoke and fumes into aircraft, creating significant safety concerns. These strikes compromised engine fan blades, engaging LRDs designed to maintain engine balance and prevent further damage. During the March incident in particular, “a large amount of engine oil flowed into the hot section of the engine causing toxic smoke and fumes to enter the cockpit or cabin via the environmental and aircraft pressurization systems.”
The National Transportation Safety Board (NTSB) released a preliminary report in December 2024 regarding the December 2023 incident, noting that CFM International and Boeing were developing a software design update. CFM International, part of a joint venture between GE Aerospace and Safran Aircraft Engines, has maintained that LRDs, used in aviation for over two decades, function as designed. They affirmed that “birds in these incidents significantly exceeded the size and weight of regulatory bird ingestion certification standards,” yet engine performance remained as expected under these conditions.
