Airworthiness Directives; Hamilton Sundstrand Corporation Model 568F-1 Propellers.

This amendment supersedes an emergency airworthiness directive (AD) 2002-05-51 that was sent previously to all known U.S. owners and operators of Hamilton Sundstrand Corporation (formerly Hamilton Standard Division) model 568F-1 propellers. That AD requires replacement of propeller blades, part numbers (P/N's) R815505-2 and R815505-3, that have a serial number (SN) of FR1698 or lower, with serviceable propeller blades, a prohibition against installing any propeller blades, P/N's R815505-2 and R815505-3, that have a SN of FR428 or lower, that were previously installed on an ATR-42-400 or an ATR-72 airplane, on any other airplane, and initial and repetitive ultrasonic shear wave inspection of the blade tulip on installed blades P/N's R815505-2 and R815505-3, that have a SN of FR1698 or lower. This amendment requires those same actions, and also requires replacing certain SN blades before further flight. This amendment also requires initial and repetitive ultrasonic shear wave inspections of the blade tulip on installed blades, P/N's R815505-2 and R815505-3, that have a SN of FR1698 or lower until they are replaced. This amendment is prompted by a report of a blade failure that resulted in damage to the airplane. The actions specified in this AD are intended to prevent blade failure due to corrosion-induced fatigue, which could result in blade separation and possible loss of airplane control.