AD/F50/91 Elevator Leading Edge (Cth)

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 39.001(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 F50 (F27 Mk 50) Series Aeroplanes

AD/F50/91 Elevator Leading Edge 6/2005

Applicability:

All Model F27 Mk 050, Mk 0502, and Mk 0604 aircraft.

Requirement:

1.    Inspect the elevator leading edge sections in accordance with Part 2 Accomplishment Instructions of Fokker Service Bulletin (SB) F50-55-012, dated 11 October 2004, or a later CAA-NL approved revision.

2.    For aircraft equipped with the “divided type” elevator leading edge sections, inspect in accordance with Part 2 Accomplishment Instructions of SB F50-55-12, or a later CAA-NL approved revision.

3.    For aircraft equipped with the “divided type” elevator leading edge sections, modify the leading edge sections in accordance with Part 2 Accomplishment Instructions of Fokker SB F50-55-13, dated 11 October 2004, or a later CAA-NL approved revision.

Note:  Netherlands CAA AD NL-2005-001 refers.

Compliance:

1.    Within 6 months after 9 June 2005.

2.    Within 6 months after the Requirement 1 inspection, and thereafter at intervals not to exceed 6 months; until accomplishment of Requirement 3 of this Directive.

3.    Within 2 years after 9 June 2005.

This Airworthiness Directive becomes effective on 9 June 2005.

Background:

Reports were received of elevator leading edges (divided type) that appeared to be loose.  Inspection revealed the fastener holes in the leading edge sections to be elongated and worn.  Investigation has shown that vibration induced by the propeller slipstream as the most likely cause.  This Directive requires inspections and eventual modification of the divided elevator leading edges.

David Villiers
Delegate of the Civil Aviation Safety Authority

26 April 2005