COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Mitsubishi MU-2 Series Aeroplanes AD/MU-2/40 Placard - Use of Reverse Thrust 10/87 DM Applicability: All model MU-2-( ) fitted with Garrett TPE-331 turboprop engines to which Hartzell model HC-B4(T,M)N-5( ) propellers are fitted. Requirement: Install a temporary placard in a suitable position in the cockpit worded as follows: "Until propellers are modified to Hartzell SB 153, avoid the use of full reverse pitch." Compliance: By 30 October 1987. Background: During the past several months the four bladed steel hub propeller fitted to MU-2-( ) series a/c has experienced failure of the pitch change rod P/N B-3018S-2. Failure has occurred during ground operation with application of full reverse pitch. Rod failure in this position will cause the propeller to travel deeper into reverse which could cause severe asymmetric thrust conditions or unacceptable engine overtemperature conditions.