AD 69-09-03 R3 61 FR 21071

This amendment revises an existing airworthiness directive (AD), applicable to Sensenich Propeller Manufacturing Company Inc. Models M76EMM, M76EMMS, 76EM8, and 76EM8S() metal propellers, that currently restricts operators from continuously operating the propeller at engine speeds from 2,150 to 2,350 revolutions per minute (RPM) and specifies propeller inspection and rework or replacement. This amendment eliminates the requirement to add tachometer markings on aircraft with certain additional Textron Lycoming O-360 series reciprocating engines with solid crankshafts installed, and updates the referenced Sensenich Propeller Company Inc. service bulletin to the latest revision. Reworking of all affected propeller models remains a requirement of the AD, regardless of engine installation. This amendment is prompted by inquiries concerning tachometer red arc restrictions on certain Textron Lycoming O-360 series reciprocating engines with solid crankshafts. The actions specified by this AD are intended to prevent propeller blade tip fatigue failure, which can result in loss of control of the aircraft.