FAA mandates actuator replacement on Boeing 787s

The Federal Aviation Administration (FAA) has issued a new airworthiness directive requiring the replacement of specific actuators on the leading edge slats of certain Boeing 787 aircraft. This directive, published on October 8, will take effect on November 12, 2026, and applies to the 787-8, 787-9, and 787-10 models.

Actuators linked to high-lift devices

The affected actuators control the leading edge slats, which are high-lift devices on the wings that help generate lift during takeoff and landing. The FAA is concerned that these slats could move to an unintended position without alerting the pilots, which could compromise flight safety.

New hardware replaces monitoring system

The directive replaces a previous monitoring system with a hardware correction. It specifically targets the external leading edge slats at positions 2 and 11, requiring the replacement of geared rotary actuators with newer LEOLA actuators that include a locking function. This change is outlined in Boeing's technical bulletin and must be carried out in accordance with updated guidelines.

Timeline and deadlines for replacement

The November 12, 2026, date marks the effective date of the regulation, not a deadline for completion. Specific deadlines for replacing the actuators are detailed in Boeing's bulletin, which the FAA has incorporated into the directive. Airlines are given flexibility to complete the work within these outlined timelines.

Issue traced back to 2019

The problem with the slats was first identified in 2019, when five external slat actuators failed during taxiing. These failures led to discrepancies between the commanded and actual positions of the slats. The FAA later discovered that slats could also move without triggering any cockpit alerts, a risk that required new safety measures.

Temporary rules still in place until 2026

Until the new directive takes effect, airlines must continue following previous safety requirements. These include restrictions on flap retraction after landing in icy conditions and procedures to clear ice, snow, or melted snow from the slats. These rules are specifically tied to the "after landing" phase and do not apply to flight operations in icy conditions.

New maintenance requirement added

In addition to replacing the actuators, airlines must include a new maintenance task in their programs. This involves checking the coupling brake of each slat drive unit. The new task replaces the temporary measures from 2019 and ensures continued monitoring of the system even after the hardware update.

Estimated cost per aircraft

The FAA estimates that replacing the actuators will cost approximately $32,375 per Boeing 787, with $31,610 for parts and $765 for labor. For the 174 affected aircraft in the United States, the total cost is expected to be around $5.63 million. Additional costs for operational checks and flight manual updates are separate and not included in this estimate.