Airworthiness Directives; Airbus Model A300 B2 and A300 B4 Series Airplanes; A300 B4-600, B4-600R, C4-605R Variant F, and F4-600R (Collectively Called A300-600); and A310 Series Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to all Airbus Model A300 B2 and A300 B4 series airplanes; A300 B4-600, B4-600R, C4-605R Variant F, and F4-600R (collectively called A300-600); and A310 series airplanes. This AD requires, for certain airplanes, identifying the part number of the landing gear selector valves. For all airplanes, this AD requires repetitive maintenance tasks or operational tests of the landing gear selector valves, and replacing discrepant valves with certain new valves. This action is necessary to prevent failure of the landing gear selector valves, which could result in residual pressure on the retraction chamber side of the electro-hydraulic selector, and consequent uncommanded retraction of the landing gear when the airplane is on the ground. This action is intended to address the identified unsafe condition.