On 1 November 2017, an Aeroprakt A22LS Foxbat was involved in a landing accident that resulted in the aircraft coming to rest inverted adjacent to the airstrip. Examination of the aircraft following the occurrence, identified that the right rudder control cable had failed in flight. Significant damage to the left rudder control cable was also identified at a similar location to where the right cable had failed.
Recreational Aviation Australia requested that the ATSB perform a detailed technical examination of the aircraft’s rudder control cables and associated rigging. The scope of this examination was limited to the identification of factors that contributed to the damage and subsequent failure of the cable. To facilitate this work, the ATSB initiated an external investigation under the Transport Safety Investigation Act 2003.
The ATSB analysis found that the right cable failed as a result of fatigue failure associated with significant wear of the individual wires (see Figure 1). Although the left hand cable did not fail, it was found to be unserviceable based on the standards set in the aircraft maintenance manual, due to fatigue fracturing of the wire strands. Both cables were found to be within material specifications.
Figure 1: Wear and associated fatigue fracture of wires on the right rudder control cable
Source: ATSB
Any further enquiries in relation to the accident investigation should be directed to Recreational Aviation Australia.
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The information contained in this update is released in accordance with section 25 of the Transport Safety Investigation Act 2003.