Washington DC, 23 March - The Federal Aviation Administration (FAA) has issued an Airworthiness Directive (AD) mandating inspections of Boeing 777 aircraft due to concerns over wing cracks. This directive, effective from April 23, 2025, applies to all variants of the Boeing 777, including the -200, -200LR, -300, -300ER, and 777F models. The action stems from the discovery of structural issues that could potentially compromise the safety and integrity of these widely used widebody aircraft, prompting a rigorous response from both regulators and the manufacturer.
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The origins of this directive trace back to the identification of a 5-inch crack on the upper wing skin of a Boeing 777’s right wing at wing station 460. This initial finding, reported by Boeing, sparked a broader investigation into the fleet’s structural health. Subsequent reports revealed two additional incidents of cracking at fastener locations 6 and 7, where cracks had propagated in a spanwise direction. Notably, these cracks were only detected during repairs of adjacent fasteners, highlighting the insidious nature of the problem. If left unaddressed, such cracking could undermine the structural integrity of the aircraft, potentially leading to catastrophic consequences like loss of control. The FAA emphasized that the safety of the flying public necessitated immediate action, culminating in the issuance of this comprehensive AD.
The directive mandates repetitive inspections of the upper wing skin around specific fastener locations, shifting from the initially proposed ultrasonic (UT) inspections to open-hole high-frequency eddy current (HFEC) inspections. This change was informed by evidence that HFEC methods are more effective at detecting the particular type of cracks observed. Operators are required to follow procedures outlined in Boeing Alert Requirements Bulletin 777-57A0125 RB, issued on July 25, 2023, which details routine checks and on-condition actions such as repairs when cracks are found. The FAA estimates that this AD will impact 323 U.S.-registered Boeing 777s, with compliance costs for operators reaching approximately $1,576,240 per inspection cycle. These costs reflect the labor-intensive nature of the inspections and the potential need for repairs, which could involve oversizing fastener holes when interference fit fasteners are removed.
The regulatory process for this AD began with a Notice of Proposed Rulemaking (NPRM) in November 2023, followed by a Supplemental NPRM (SNPRM) in September 2024, which refined the inspection requirements based on Boeing’s updated findings. Feedback from operators like FedEx, which noted no cracks in aircraft with fewer than 48,000 flight hours, and Air France, which sought clarification on compliance timelines, influenced the final directive. The FAA has also allowed for potential extensions of inspection intervals if operators provide substantial data demonstrating an acceptable level of safety, reflecting a balance between stringent oversight and operational feasibility. Boeing has expressed support for the FAA’s directive, collaborating closely with operators to implement the required inspections and repairs. The company’s proactive reporting of the additional cracking incidents underscores its role in addressing this safety concern. Meanwhile, the FAA remains vigilant, with provisions for alternative methods of compliance (AMOCs) to accommodate specific operator needs, provided they maintain safety standards. This AD represents a critical step in ensuring the continued airworthiness of the Boeing 777 fleet, a backbone of long-haul aviation, as regulators and manufacturers work together to mitigate risks and uphold the highest safety standards in the skies.