The Federal Aviation Administration of the United States (FAA) has issued a new Airworthiness Directive (AD) for certain Boeing 737 MAX aircraft following a report of improper installation of spoiler control cables. This installation error caused unintended spoiler movement, including an incident involving a flight spoiler «hardover.» The FAA has classified this issue as an unsafe condition that could result in the loss of aircraft control if left unaddressed.
The problem was identified after an incident in which a flight spoiler experienced a «hardover,» an extreme condition where the spoiler becomes stuck in a fully deployed position. Further investigation revealed the potential for multiple flight spoilers to become stuck simultaneously on the same wing. This scenario could exceed the aircraft’s lateral control capability, significantly increasing the risk of loss of control during flight.
In response, the FAA has mandated a one-time inspection of the clearance between the spoiler control cables and adjacent structures. The directive also includes a requirement to carry out necessary repairs if the inspection reveals improper clearance.
This AD applies to Boeing 737-8, 737-9, and 737-8200 (737 MAX) aircraft, as specified in the Boeing Alert Requirements Bulletin 737-27A1325 RB, dated July 14, 2023. The FAA has stipulated that the inspection must be completed by January 6, 2025.
The FAA’s decision follows the publication of a Notice of Proposed Rulemaking (NPRM) in March 2024, which outlined similar provisions. The agency received comments from various stakeholders, including Boeing, United Airlines, and the Air Line Pilots Association (ALPA), who supported the NPRM without changes. However, some commentators, such as SunExpress Airlines and The Foundation for Aviation Safety, requested that the FAA implement a more urgent compliance timeline, citing concerns about potential catastrophic failures.
The FAA reviewed these comments and conducted a risk analysis, concluding that a compliance timeline of 36 months was appropriate given the nature of the issue. The agency emphasized that the condition is unlikely to occur under normal operating conditions and that the affected aircraft have been identified through Boeing’s production processes to ensure newer aircraft are not impacted.
Financial Impact
The FAA estimates that 207 Boeing 737 MAX aircraft registered in the United States will be affected by the directive. Operators are expected to incur costs for the required inspections, estimated at $85 per aircraft. If repairs are needed, additional costs will range from $170 to $425 per aircraft, depending on the extent of the damage.
The FAA’s decision to proceed with the AD follows a detailed review of available data and public comments. While the agency did not adopt the suggestion for a shorter compliance timeline, it has allowed operators to request alternative compliance methods if necessary.
