COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Fokker F50 (F27 Mk 50) Series Aeroplanes
AD/F50/59 Engine Electronic Control System 2/93
Applicability: F27 Mk 050 aircraft Serial Numbers 20103 to 202427 inclusive.
Requirement: Action in accordance with Fokker Service Bulletin F50-73-013 dated 6 July 1992.
Fokker Component Service Bulletin F7941-006-73-03 also refers.
Note: RLD Airworthiness Directive BLA 92-086 dated 18 September 1992 refers.
Compliance: Prior to 4 February 1994.
Background: The engine electronic control (EEC) is designed in such a way that if an EEC failure occurs the affected engine fuel control will remain at the last selected power setting. This means that there is no power response from the affected engine when the power levers are moved forward (fail-fixed feature) unless manual mode is selected by the pilot. This Directive requires that the EEC be replaced with a modified version which automatically selects manual mode if an EEC failure occurs below the 17 degrees power lever angle (approach position).