Summary
This document proposes the supersedure of an existing airworthiness directive (AD), applicable to Teledyne Continental Motors (TCM) O-200 series reciprocating engines, that currently requires resetting engine timing to 24 deg. Before Top Center (BTC). This action would return to the 28 deg. BTC engine timing for those engines equipped with improved cylinders that have strengthened heads. This action would also add license-built Rolls-Royce, plc O-200 series engines to the AD's applicability and drop the TCM O-200C model which never went into production. This proposal is prompted by the availability of improved cylinders. The actions specified by the proposed AD are intended to prevent possible cylinder cracking with subsequent loss of engine power.