Airworthiness Directives; Piper Aircraft, Inc. Airplanes

We propose to supersede Airworthiness Directive (AD) 96-12-12, which applies to certain Piper Aircraft, Inc. Models PA-31, PA-31-300, PA-31-325, and PA-31-350 airplanes. AD 96-12-12 currently requires a one-time inspection of the bulkhead assembly at fuselage station (FS) 317.75 for cracks and the installation of one of two reinforcement kits determined by whether cracks were found during the inspection. Since we issued AD 96-12-12, bulkhead cracks were found on airplanes that had complied with AD 96-12-12 and on additional airplanes not affected by AD 96-12-12. This proposed AD would require repetitive inspections of the bulkhead assembly at FS 317.75 for cracks, repair of cracks as necessary, and the installation of a reinforcement modification. We are proposing this AD to correct the unsafe condition on these products.