AD/BEA 121/27 Amdt 3 Control Column Handgrip Fitting (Cth)

AIRWORTHINESS DIRECTIVE

On the commencement date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below repeals Airworthiness Directive (AD) AD/BEA 121/27 Amdt 2 and issues the following AD under subregulation 39.001 (1) of CASR 1998 and subsection 33 (3) of the Acts Interpretation Act 1901. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct an 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.

de Havilland Support Beagle B.121 (Pup) Series Aeroplanes

AD/BEA 121/27 Amdt 3 Control Column Handgrip Fitting 17/2016

Applicability:

All models of de Havilland Support Beagle B.121 (Pup) Series aeroplane.

Requirement:

Action in accordance with Mandatory Beagle Pup service bulletin (SB) B121/95 Revision 4 issued 8 July 1996.

Compliance:

As specified in the Requirement Document.

This AD commences on 29 August 2016.

Background:

Cases have been reported of fractures of the handgrips (Part No. BE45-10283) fitted to the control columns of bulldog aircraft. These handgrips are identical to those fitted to Pup aircraft. Failures may be more likely on aircraft operating in climates susceptible to high levels of ultraviolet radiation.

AD/BEA 121/27 Amendment 1 was raised in response to two recent occurrences of in‑flight failure of the control column handgrips during aerobatics. The failed handgrips had no evidence of surface cracking. This AD introduces revised inspection procedures to ensure that the handgrips are airworthy.

Further testing has established that non destructive inspection is not adequate to detect degradation of strength. AD/BEA 121/27 Amendment 2 lifed the handgrips at five years.

AD/BEA 121/27 Amendment 3 is issued to incorporate Beagle Pup SB B121/95 Revision 4. Revision 4 provides two options to the registered operator of the aircraft, namely; option 1 requires replacement of the handgrips at intervals of 5 years if the aircraft and the handgrips are not covered when not in use. Option 2 requires replacement of the handgrips at intervals of 10 years if the aircraft and the handgrips are kept covered when not in use.

Pieter van Dijk
Delegate of the Civil Aviation Safety Authority

8 August 2016