AD/DHC-3/30 Amdt 1 Elevator Connecting Rod (Cth)

AIRWORTHINESS DIRECTIVE

On the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/DHC-3/30 and issues the following 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.

DHC-3 (Otter) Series Aeroplanes

AD/DHC-3/30 Amdt 1 Elevator Connecting Rod 1/2009

Applicability:

All Model DHC-3 aircraft.

Requirement:

1.    Visually inspect the elevator pushrod (part number C3-CF-167 or replacement pushrod part number C3-CF-633-1); and the elevator pushrod to rear quadrant attachment bolt (part number AN174-16 or replacement bolt part number NAS1954-24D) and associated hardware.

The inspection should concentrate on the detection of bowing of the pushrod, cracking of the pushrod threaded ends or bending of the attachment bolt.  If evidence of component damage is found, before further flight, replace the damaged parts in accordance with de Havilland Service Bulletin (SB) No.3/35 Revision A and SB No.3/43 original issue, or later Transport Canada approved revisions; except that attachment bolt part number AN174-16 may be used in lieu of bolt part number NAS1954-24D until Requirement 2 of this Directive comes into effect.  If bolt part number AN174-16 is replaced with bolt part number NAS1954-24D, the rudder pushrod to rear quadrant attachment bolt and associated hardware are also required to be replaced at the same time with hardware as specified in SB No.3/43 original issue, or later Transport Canada approved revision.

2.    Replace the elevator pushrod to rear quadrant attachment bolt and associated hardware in accordance with SB No.3/43 original issue, or later Transport Canada approved revision.  Simultaneously, unless already accomplished, replace the rudder pushrod to rear quadrant attachment bolt in accordance with SB No.3/43 original issue, or later Transport Canada approved revision.

3.    Whenever a parked aircraft has been exposed to jet, propeller, or helicopter blast or winds with an estimated mean velocity of 55 km/h with gusting up to 100 km/h, compliance with Requirement 1 must be accomplished before further flight regardless of whether the new components of Requirement 2 have been installed or not.  After exposure to these wind velocities visually inspect the remainder of the elevator control circuit for damage in accordance with de Havilland SB No.3/35 Revision A, or later Transport Canada approved revision.

Note:  Transport Canada AD CF-85-04 refers.

Compliance:

1.    Unless already accomplished, within 50 flight hours after 15 January 2009.

2.    Unless already accomplished, within 100 flight hours after 15 January 2009.

3.    As specified in Requirement 3.

This Amendment becomes effective on 15 January 2009.

Background:

In-service damage has occurred to the elevator pushrod and attachment bolt to the elevator quadrant in the stub fin.  The damage usually takes the form of bowing of the pushrod and bending of the attachment bolt, caused by high external loads applied to the elevator due to strong gust loading while the aircraft is parked.  Similar problems could develop with the rudder pushrod to rear quadrant attachment bolt.

Amendment 1 is issued to introduce the requirements of Transport Canada AD
CF-85-04, which supersedes the original requirements of this Directive.

David Villiers
Delegate of the Civil Aviation Safety Authority

27 November 2008