Summary
We propose to adopt 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 proposed AD was prompted by a report of a crack in the forward cargo door selector valve pipe located in the avionics bay opposite to line replaceable unit racking. This proposed AD would require replacing a certain aluminum high pressure pipe with a new corrosion resistant stainless steel pipe. We are proposing this AD to prevent cracking in the forward cargo door selector valve pipe which could impact the 90 VU avionics line replaceable unit, and could result in multiple computer failures, affecting flight safety.