AD/F27/155 - Aileron Spring Tab Balance Unit (Cth)

COMMONWEALTH OF AUSTRALIA (Civil Aviation Safety Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES

AIRWORTHINESS DIRECTIVE For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CASR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.

Fokker F27 Series Aeroplanes

AD/F27/155 Aileron Spring Tab Balance Unit 7/2003

Applicability: All Model F.27 Mk.100 through Mk. 700 series aircraft.

Requirement: Inspect, and if necessary, replace the aileron spring tab balance units in accordance with Part 2, Accomplishment Instructions of Fokker Service Bulletin F27/27-137, dated 19 March 2003.

Note: Netherlands CAA AD 2003-037 refers.

Compliance: Before 1 May 2005, unless already accomplished.

This Airworthiness Directive becomes effective on 10 July 2003.

Background: The CAA-NL received a report of an in- flight incident where the flight crew had to apply aileron trim during heavy turbulence. After landing, inspection revealed that the left hand aileron was hanging down approximately 25 mm. A subsequent detailed inspection uncovered damage to the stop of the aileron spring tab; and the skin was damaged due to overtravel of the push-pull rod. After removal from the aircraft, the affected aileron was inspected and a crack was found in the upper inboard attachment lug of the aileron spring tab balance unit housing. Failure of all four attachment lugs could result in total loss of roll control for the affected wing.