EASA AD BR-2023-05-02R2
Flight Controls - Aileron Control System Backlash - Inspection
Summary
The Brazilian Airworthiness Directive AD No. 2023-05-02R2 is an updated regulatory document issued by ANAC addressing the inspection and maintenance of the aileron control system backlash on Embraer ERJ 190-400 aircraft. It mandates inspections and potential replacement of wing aileron bearings and bushings to ensure compliance with safety standards and prevent excessive control system backlash.
What Changed
This directive supersedes AD No. 2023-05-02R1 and introduces a terminating action to the inspection requirements. It expands the compliance scope by including detailed inspection intervals based on flight hours and adds specific procedures for inspection, functional checks, and replacement of affected components as per Embraer Service Bulletin Nº 190E2-27-0026 revision 09.
Why It Matters
Excessive backlash in the aileron control system can cause Limit Cycle Oscillation, leading to unacceptable vibration levels and reduced aircraft controllability, posing a significant flight safety risk. Operators and maintenance teams must address this issue promptly to maintain airworthiness and avoid operational disruptions or safety incidents.
What To Do
Operators of Embraer ERJ 190-400 aircraft must perform initial and repetitive inspections of the left and right wing aileron control systems within specified flight hour intervals. If inspections reveal migrated bushings, broken sealant, or backlash exceeding 1.06 mm, immediate replacement of bearings and bushings is required before further flight. Compliance deadlines vary depending on flight hours since new but generally require action within 750 to 3,000 flight hours after May 18, 2023.