Summary
The FAA proposes to supersede an existing airworthiness directive (AD) for certain MT-Propeller Entwicklung GmbH variable pitch and fixed pitch propellers manufactured before 1995 which had not been overhauled since April 1994. That AD currently requires overhauling the propeller blades and performing initial and repetitive visual inspections of affected propeller blades. That AD also requires removing all propeller blades from service with damaged erosion sheath bonding or loose erosion sheaths and installing any missing or damaged polyurethane protective strips. This proposed AD would require the same actions. This proposed AD results from the need to clarify the population of affected propellers previously listed in AD 2006-05-05. We are proposing this AD to prevent erosion sheath separation leading to damage of the airplane.