The FAA has issued an airworthiness directive (AD) for mostly older airplanes that have certain Hartzell propellers. The FAA said the AD resulted from two incidents where "Z-shank" blades failed and separated. Teardown inspections detected corrosion in the blade bores. The AD affects about 1,200 aircraft in the U.S. registry.
The AD goes into effect on October 14 and requires the inspection of the propeller blades and other critical propeller parts. " The positive for some aircraft owners is that no action is required if the time-since-overhaul (TSO) of the propeller is 10 years or less on the AD's effective date or the propeller assembly was inspected under a previous Hartzell service bulletin," said Luis Gutierrez, director of regulatory and certification policy. For aircraft where the TSO is not known, the service bulletin has not been complied with, or have a TSO date that is 10 years or older, the FAA has set up deadlines for completing the inspections, ranging from 12 to 36 months.
The affected aircraft may include the Cessna 172, 175, 190, 195, and 421; the Piper PA-23, PA-24, and PA-25; and several other models from Beechcraft, Aero Commander, Grumman, and Mooney. For more information, see AOPA's issue brief.
September 26, 2005