COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Pratt and Whitney Canada Turbine Engines - PW100 Series
AD/PW100/4 Fuel Pump Input Drive Shaft 7/91
Applicability: PW123, PW123AF, PW124B, PW125B, PW126 engines as detailed in Pratt and Whitney Canada Service Bulletin No. 20946 Rev. 1.
Requirement: Action in accordance with the Technical Requirements of Transport Canada Airworthiness Directive No CF-91-02.
Compliance: Prior to 31 October 1991.
Background: The engine manufacturer has determined that fuel pump input drive shaft torsional vibration can induce oscillations of the main fuel control governor, which may result in large torque fluctuations or torque drop during flight. This Directive requires the modification of the fuel pump to incorporate an input drive shaft with increased torsional stiffness.