Summary
We propose to supersede Airworthiness Directive (AD) 98-19-15 R1 and AD 2000-03-17, which apply to M7 Aerospace LP SA226 and SA227 series airplanes equipped with certain pitch trim actuators. AD 98-19- 15 R1 currently requires you to incorporate changes into the Limitations Section of the FAA-approved Airplane Flight Manual (AFM) if certain part number (P/N) pitch trim actuators are installed. AD 2000- 03-17 requires repetitive inspections and repetitive replacements of the pitch trim actuator. The repetitive inspection and repetitive replacement times vary depending on the combination of airplane model and pitch trim actuator P/N installed. We are proposing this AD because we have determined that reliance on critical repetitive inspections on aging commuter-class airplanes carries an unnecessary safety risk when a design change exists that could eliminate or, in certain instances, reduce the number of those critical inspections. Consequently, this proposed AD would retain allof the actions of the previously referenced ADs, place life limits on certain P/N pitch trim actuators, and require the replacement of certain P/N pitch trim actuators with one of an improved design. Once installed, the improved design pitch trim actuator would terminate the AFM limitations in this proposed AD and reduce the repetitive inspection and repetitive replacement requirements. We are proposing this AD to detect excessive freeplay or rod slippage in the pitch trim actuator, which, if not detected and corrected, could result in pitch trim actuator failure. We are also proposing this AD to lessen the severity of pitch upset if a pitch trim actuator mechanical failure occurs. These conditions could lead to possible loss of control.