2013-09 Multiple

Hoffman Propeller has informed EASA about reported occurrences of unauthorized overhaul/repair of fixed-pitch propellers. These propellers are suspected to have been overhauled/repaired without authorisation from Hoffmann, and consequently, work may have been carried out without using approved procedures. Such actions could seriously affected the safe operation of the propeller.
At this time, the safety concern described in this SIB is not considered to be an unsafe condition that would warrant Airworthiness Directive (AD) action under EU 748/2012, Part 21.A.3B.