Installation of a United Aircraft of Canada PT6A-27 or PT6A-34 engine in accordance with Serv-Aero Engineering, Inc. Drawing List 537761, revision dated July 15, 1976, or later FAA Sealed revisions. FAA approved Serv-Aero Engineering, Inc. Airplane Flight Manual dated November 30, 1976, or later FAA approved revisions, is required as part of this installation for the PT6A-27 engine. FAA approved Serv-Aero Engineering, Inc. Airplane Flight Manual dated July 23, 1976, or later FAA approved revisions, is required as part of this installation for the PT6A-34 engine. Aircraft incorporating the PT6A-34AG engine and engines converted to the PT6A-34AG configuration per Ayres Corporation Service Bulletin 001 dated August 25, 1977, or later FAA approved revisions, require Ayres Corporation Airplane Flight Manual (AFM) dated August 29, 1977, or later approved revisions. This AFM replaces the Serv-Aero Engineering, Inc. AFM and basic S-2R AFM. View PDF on drs.faa.gov ↗

The STC PDF is authoritative: installation instructions, ICA requirements and limitations.