Airworthiness Directives; Airbus Airplanes

We propose to supersede Airworthiness Directive (AD) 2007-13- 08, for certain Airbus Model A318, A319, A320, and A321 series airplanes. AD 2007-13-08 currently requires repetitive inspections of the auxiliary power unit (APU) starter motor, APU inlet plenum, and APU air intake for discrepancies; repetitive cleaning of the APU air intake, and applicable corrective actions. Since we issued AD 2007-13- 08, a determination was made that the unsafe condition could occur on additional airplanes. This proposed AD would expand the applicability in AD 2007-13-08, and include an optional terminating installation for the repetitive actions. We are proposing this AD to address the unsafe condition on these products.