FAA Proposes Airworthiness Directive for Airbus A350 Actuators

The Federal Aviation Administration (FAA) has issued a Notice of Proposed Rulemaking (NPRM) for a new Airworthiness Directive (AD) that would affect all Airbus A350-941 and A350-1041 aircraft. The proposed mandate addresses a potential unsafe condition related to primary flight control actuators that may have been subjected to mechanical overloads during factory acceptance testing.

This action by the FAA follows a similar directive issued by the European Union Aviation Safety Agency (EASA), which is the primary certifying authority for Airbus products. EASA's directive, AD 2025-0152, was prompted by a determination that certain flight control actuators could have sustained latent damage. Such damage, if unaddressed, could potentially lead to a degradation of flight control capabilities, prompting the regulatory actions to ensure continued airworthiness across the global A350 fleet.

Background of the Directive

Regulatory authorities were alerted to the issue after an internal investigation determined that specific primary flight control actuators may have been exposed to excessive mechanical loads. This occurred during the acceptance testing phase of production before the components were installed on aircraft. The concern is that this overload could introduce damage that is not immediately detectable but could manifest later in the component's service life.

In response to these findings, Airbus issued an Alert Operators Transmission (AOT) to inform airlines of the potential issue and provide instructions for the necessary inspections and corrective actions. The proposed FAA AD aims to formalize these requirements for U.S.-registered aircraft, making the inspection and replacement procedures mandatory to mitigate the identified risk.

Technical Details and Affected Components

The components at the center of the proposed AD are specific primary flight control actuators, including the Electro-Hydrostatic Actuator (EHA) and the Electrical Backup Hydraulic Actuator (EBHA). These advanced components are critical to the A350's fly-by-wire flight control system, which translates pilot inputs into movements of the aircraft's control surfaces (e.g., ailerons, elevators, and rudder).

The A350 utilizes a more electric architecture, with EHAs and EBHAs providing hydraulic power locally without relying solely on a centralized hydraulic system. This design offers weight savings and increased redundancy. However, the potential for latent damage from overstressing during testing poses a risk that requires proactive fleet-wide checks to ensure the integrity of these critical systems.

The proposed directive would require operators to identify the serial numbers of the installed actuators and, if they fall within the affected batch, perform detailed inspections. If any damage or non-conformance is found, the actuator must be replaced.

Next Steps and Operator Requirements

The FAA has published the NPRM in the Federal Register to allow for a public comment period. During this time, airlines, maintenance organizations, and other industry stakeholders can provide feedback on the proposed rule, including its technical feasibility and economic impact. After the comment period closes, the FAA will review the submissions and may issue a final rule.

Once the AD is finalized, operators of Airbus A350-941 and -1041 aircraft in the United States will be required to comply with its terms within a specified timeframe. This typically involves incorporating the inspection and modification tasks into their regular maintenance schedules. The cost of compliance will include the labor for inspections and the price of any replacement actuators that are required.

Why This Matters

This proposed Airworthiness Directive underscores the rigorous and collaborative nature of global aviation safety oversight. The coordination between Airbus, EASA, and the FAA ensures that potential safety issues are addressed systematically across the entire fleet, regardless of where the aircraft operate. For A350 operators, the directive introduces a mandatory maintenance action that is essential for ensuring the long-term structural and operational integrity of their flight control systems. While potentially disruptive, such proactive safety measures are fundamental to maintaining the industry's high safety standards.