AD FAA-2012-1324

We are adopting a new airworthiness directive (AD) for all 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), and Model A310 series airplanes. This AD was prompted by a report of a crack in the selector valve pipe of the forward cargo door located in the avionics bay opposite the line replaceable unit racking. This AD requires replacing a certain aluminum high pressure pipe with a new corrosion resistant stainless steel pipe. We are issuing this AD to prevent cracking in the selector valve pipe of the forward cargo door which could impact the 90 VU avionics line replaceable unit, and could result in multiple computer failures, affecting flight safety.