The FAA published two airworthiness directives this week that affect the Piper general aviation fleet. A final rule published on Monday affects 3,100 Piper Comanches (models PA-24, PA-24-250, and PA-24-260), requiring inspections of the stabilator horn assembly, at a cost of about $1,000 per airplane. If the assembly needs to be replaced, it would cost another $1,600. Failure of the stabilator horn could lead to a loss of pitch control in flight, the FAA said. A proposed rule published on Tuesday affects about 1,000 Piper twins, models PA-31, PA-31-325, and PA-31-350. The rule would supersede an existing AD that requires repetitive inspections of the exhaust system.
"Since we issued that AD, forced landings of aircraft have occurred due to exhaust system failures upstream of aircraft turbochargers and between recurring detailed inspections," the FAA said. "This proposed AD would require both visual and detailed repetitive inspections, expanding the inspection scope to include the entirety of each airplane exhaust system. We are proposing this AD to prevent the possibility of an inflight powerplant fire due to an exhaust system failure." Inspections would cost up to about $400, and the FAA says it can't predict what it might cost to repair or replace the exhaust system, if needed. The proposed rule is open for comments until Nov. 2.