On 7 June 2013, stabiliser trim control cable, pulley and drum damage were discovered on a Boeing 737-800 undergoing scheduled maintenance at Auckland. The Investigation found the damage to have been due to a rag which was found trapped in the forward cable drum windings and concluded that the integrity of the system which provided for stabiliser trim system manual control by pilots had been compromised over an extended period. The rag was traced to a specific Australian maintenance facility which was run by the Operator's parent company and which was the only user of the particular type of rag.