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 propose to supersede 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. The existing AD currently requires 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 Model PA-46-350P airplanes; and inserting a copy of the AD into the pilot's operating handbook (POH) for certain airplanes. Since we issued that AD, the manufacturer has revised related service information and added an airplane model to the list of affected airplanes. This proposed AD would retain the actions required by AD 99-15-04 R1, add certain Model PA-46R-350T airplanes to the Applicability section, expand the applicability to include other T.I.T. systems, and incorporate new service information. We are proposing 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.