FAA Orders Boeing 737 MAX Crack Inspections

US aviation regulators have finalized a new airworthiness directive requiring operators to inspect nearly 500 Boeing 737 MAX aircraft for structural fuselage cracks, marking the latest regulatory requirement for the aircraft manufacturer as it works through broader safety and manufacturing challenges.

The finalized rule, unveiled Thursday by the Federal Aviation Administration (FAA), takes effect Sept. 10. It applies to an estimated 471 US-registered Boeing 737 MAX 8, MAX 9, and MAX 8-200 aircraft. Under the order, airlines must inspect a structural reinforcement known as a forward bear strap, a metal sheet that reinforces fuselage areas near doorways and emergency exits, located around the right-hand forward service door and adjacent to the forward galley.

While no cracks have been detected in the targeted 737 MAX models to date, the FAA warned that undetected damage could compromise the structural integrity of the aircraft over time. The directive was prompted by earlier reports of cracking in older "Next-Generation" (NG) 737 models. Because the 737 MAX series shares a similar design and manufacturing process with the NG models, the FAA determined the MAX fleet is susceptible to the same structural condition.

Under the mandate, airlines must execute inspections based on each aircraft's operational usage and complete any necessary repairs prior to returning affected planes to service. The directive also mandates checks on the fuselage skin of aircraft that have existing repairs.

The FAA opted against grounding the fleet, stating that the required inspection intervals afford multiple opportunities to detect and resolve cracking before structural failure can occur.

Boeing confirmed it has already modified its manufacturing process to address the structural issue in new-build aircraft. In an official statement, the Virginia-based manufacturer noted that it originally identified the issue and has been collaborating with operators on solutions for the past six years. Boeing issued inspection procedures for Next-Generation 737s in 2019, which the FAA subsequently mandated in 2021, before expanding those recommendations to the MAX fleet.

"We support both directives and continue to support our airline customers," Boeing said in a statement.

The structural inspection order follows a series of regulatory actions involving Boeing's 737 program:

• Seat Assembly Inspections: Last month, the FAA proposed a separate airworthiness directive requiring inspections of seat assemblies across 453 Boeing 737 MAX aircraft due to concerns over potential improper installation.
• MAX-7 Type Certification: Following nearly a decade of review, the FAA issued an amended type certificate and updated Production Limitation Record for the 737 MAX-7, authorizing Boeing to begin producing the model. The approval required updates to flight-control software, flightcrew alerting systems, and a redesigned engine anti-ice system to prevent inlet overheating.
• Delegated Certification: Last month, the FAA announced that Boeing would once again be permitted to certify all of its 737 MAX and 787 aircraft.

The ongoing oversight follows heightened scrutiny triggered by two fatal MAX 8 crashes in 2018 and 2019 that killed 346 people, as well as a January 2024 midflight door plug blowout on an Alaska Airlines MAX 9. The NTSB determined that four critical retaining bolts were missing when that aircraft was delivered in October 2023.

The FAA stated that safety inspectors will remain stationed at Boeing manufacturing facilities nationwide to monitor production processes, safety management systems, and quality control.