Airworthiness Directives; Piper Aircraft, Inc. (Type Certificate Previously Held by The New Piper Aircraft, Inc.) Models PA-46-310P, PA-46-350P, and PA-46R-350T Airplanes

We are superseding an existing airworthiness directive (AD) that applies to certain Piper Aircraft, Inc. Models PA-46-310P and PA- 46-350P airplanes that are equipped with a Lewis or Transicoil turbine inlet temperature (T.I.T.) gauge and associated probe. That AD currently requires cleaning, inspecting, and calibrating the T.I.T. system; replacing any T.I.T. system that fails the calibration test; repetitively replacing the T.I.T. probe on certain airplanes; and inserting a copy of the AD into the pilot's operating handbook (POH) for certain airplanes. This new AD retains the actions required by the previous AD (AD 99-15-04 R1), adds certain Model PA-46R-350T airplanes to the Applicability section, expands the applicability to include other T.I.T. systems, and incorporates new service information. This AD was prompted by the manufacturer revising related service information and adding an airplane model to the list of affected airplanes. We are issuing this AD to prevent improper engine operation caused by improperly calibrated T.I.T. indicators or defective T.I.T. probes, which could result in engine damage/failure with consequent loss of control of the airplane.