Airworthiness Directives; Airbus Model A300 B4-600, B4-600R, and F4-600R Series Airplanes, and Model C4-605R Variant F Airplanes (Collectively Called A300-600 Series Airplanes)

The FAA is adopting a new airworthiness directive (AD) for certain Airbus Model A300-600 airplanes. This AD requires an inspection to determine if certain spoiler actuators having certain part numbers are installed, and eventual replacement of all affected actuators. This AD results from failure of a distribution block, which was detected during fatigue qualification tests of certain spoiler actuators. We are issuing this AD to prevent failure of the distribution block, which could result in leakage of the hydraulic fluid that supplies those actuators. This failure could cause failure of one of the three spoiler actuators and the associated hydraulic circuits, which could result in loss of those hydraulic circuits and consequent reduced controllability of the airplane.