EASA AD US-2025-20-04
Flight Controls - Aileron Trim Actuator - Repetitive Inspections / Modification
Summary
Airworthiness Directive 2025-20-04 is a final rule issued by the Federal Aviation Administration addressing The Boeing Company Model 757 airplanes. This directive mandates repetitive inspections of the aileron trim actuator bearing and attachment lug, and introduces a required modification involving changes to the lateral control box support assembly and installation of an aileron trim actuator bracket to terminate these inspections.
What Changed
This AD supersedes AD 2019-12-13 by retaining its inspection requirements and adding a mandatory modification for certain Boeing 757 airplanes. The modification involves either changing the lateral control box support assembly and installing an aileron trim actuator bracket or replacing the existing actuator lateral control fitting with the bracket, which ends the need for repetitive inspections.
Why It Matters
The directive addresses a critical unsafe condition involving potential failure of the aileron trim actuator attachment lug, which could lead to loss of control feel, wheel centering, and lateral trim. For operators and maintenance teams, compliance ensures prevention of over-control and lateral pilot-induced oscillations, thereby maintaining safe flight and landing operations.
What To Do
Operators of Boeing 757 airplanes must continue performing the repetitive inspections as required by AD 2019-12-13 until they complete the mandated modification. The modification must be accomplished within 10,000 flight hours or 30 months from the effective date, November 6, 2025, whichever occurs first. After modification, repetitive inspections are no longer required.