Aviation safety issues and actions

Aileron servo valve adjustment

Issue number: AO-2009-021-SI-01
Who it affects: The aircraft manufacturer and aircraft type operators
Issue owner: Component manufacturer
Transport function: Aviation: Other
Background: Investigation Report AO-2009-021
Issue release date: 24 August 2010
Current issue status: Adequately addressed
Issue status justification:

The manufacturer improved its quality control process.

Safety issue description

The servo valve within the left green aileron servo was incorrectly adjusted during manufacture.

Proactive Action

Action number: AO-2009-021-NSA-036
Action organisation: Goodrich
Date: 24 August 2010
Action status: Closed
Action taken by the servo valve manufacturer The manufacturer has introduced a semi-automated setting of the bias, which replaced the previous manual setting. This will prevent the incorrect adjustment of the bias during the assembly of the servo valve. ATSB assessment of response/action The ATSB is satisfied that the action taken by the servo valve manufacturer adequately addresses the safety issue.
Last update 12 February 2014