The procedures in the aircraft maintenance manual relating to chip detector debris analysis were written in a way that could cause confusion and error. This probably influenced the actions of the maintenance personnel to release the aircraft to service with a deteriorating bearing.
The ATSB is acknowledges that the changes made to the procedures have clarified the ambiguities in the actions to be taken when debris is detected on the turbomachinery chip detector. As such, the ATSB is satisfied the safety issue has been addressed.
The Australian Transport Safety Bureau recommends that Pratt & Whitney Canada takes safety action to improve the clarity of procedures within the chip detector debris analysis section of the aircraft maintenance manual.
Pratt & Whitney Canada advised that the procedures within the chip detector debris analysis section have been clarified to remove the ambiguity on what actions should be taken in response to debris being detected on the chip detector.
The ATSB agrees that the changes made to the procedures have clarified the actions to be taken in response to the detection of debris on the chip detector. Given the effectiveness of the provided safety action, the safety recommendation and the associated safety issue are considered ‘Closed – Adequately addressed’.
