Summary
We propose to supersede Airworthiness Directive (AD) 2015-12- 08, which applies to all Airbus SAS Model A318 and A319 series airplanes and all Model A320-211, A320-212, A320-214, A320-231, A320- 232, A320-233, A321-111, A321-112, A321-131, A321-211, A321-212, A321- 213, A321-231, and A321-232 airplanes. AD 2015-12-08 requires an inspection to determine the batch number or installation date of the oxygen pipe assembly that is installed at the end of the right-hand crew distribution line, and replacement of the pipe if necessary. Since we issued AD 2015-12-08, further investigation determined that affected oxygen pipes may have been installed on more airplanes than initially identified. This proposed AD would revise the applicability to include additional airplane models and additional pipes to be replaced if necessary. We are proposing this AD to address the unsafe condition on these products.