EASA AD US-2019-12-13: Superseded by FAA AD 2025-20-04

What to do

Operators of Boeing 757 airplanes must perform repetitive inspections of the aileron trim actuator bearing and attachment lug as specified in Boeing Alert Requirements Bulletin 757-27A0159 RB dated March 29, 2019. Any damage or cracking found must be addressed with on-condition actions including inspections, repairs, or replacements. Compliance with the directive is required by July 12, 2019, with inspections to be repeated at intervals specified in the service bulletin.

Summary

FAA Airworthiness Directive 2019-12-13 is a final rule applicable to all Boeing Company Model 757 airplanes. It mandates repetitive inspections of the aileron trim actuator bearing and attachment lug for damage, along with necessary on-condition repairs to prevent failure. This directive addresses a safety issue caused by the failure of the aileron trim actuator attachment lug, which can lead to loss of lateral control.

What changed

This new airworthiness directive introduces mandatory repetitive checks of the aileron trim actuator bearing for free rotation and detailed inspections of the attachment lug for damage or cracking. It also requires on-condition actions such as high frequency eddy current inspections, repairs, or replacements as necessary. The directive is considered an interim action pending development of a permanent modification.

Why it matters

This directive is critical for aviation professionals because failure to comply could result in over-control of the airplane and lateral pilot induced oscillations, compromising safe flight and landing. Operators and maintenance teams must monitor and maintain the aileron trim actuator components to ensure continued airworthiness and regulatory compliance. The directive helps prevent potential in-flight control issues that could lead to accidents.

What to do

Summary

What changed

Why it matters

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