Encore Aviation's maintenance practices and processes related to inspections, record keeping and trend monitoring, were likely inadequate to detect the potential impending failure of safety critical components.
The ATSB notes that Encore Aviation has now provided a framework to allow records of maintenance actions to be kept for each aircraft. This included the provision to record specific values from maintenance assessments conducted, such as vibration tests. It was also noted that Encore have incorporated trend analysis processes to review previous maintenance records. This included the assessment of changes between present and previously recorded values, and further investigation of recurring events to detect potential emerging problems. These actions were expected to reduce the risk of Encore not detecting an impending failure of safety critical components to a level that is as low as reasonably practicable.
Encore Aviation advised the ATSB of improvements to their maintenance procedures. This included changes to Encore Aviation’s (Encore) Quality Control and Procedures Manual (QCPM), dated 7 December 2020, and the incorporation of cloud-based software, Aerotrack, into ‘all work practices’. The purpose of this software was to ‘track and manage engineering planning and execution of maintenance work’.
Encore reported that, ‘while the management and processes undertaken by Encore were manual and paperwork based prior to 2019, what Aerotrack and the upgrading of the QCPM and company procedures has provided is an enhanced management process that is more aligned with industry best practice and standards for the conduct, recording and storage of maintenance documentation’.
‘Aerotrack enables records to be held in perpetuity and accessed beyond the normal CASA regulatory requirements for the retention of documents’. With respect to record keeping, Encore reported that it ‘has catalogued every aircraft that is serviced into Aerotrack which records the work undertaken’ in addition to scanned copies of aircraft maintenance documentation. In addition, evidence provided by Encore showed the ‘capture and retention of vibration analysis data within Aerotrack rather than relying on data retention within the vibration test equipment itself’.
Encore has advised they have introduced trend analysis processes following the adoption of Aerotrack. These processes were incorporated into the QCPM in November 2021. These processes include the requirement to ‘review pertinent previous maintenance records in Aerotrack to establish baseline recorded values for subsequent maintenance review. This process identifies any previous recorded measurements in the operating or tolerance measurements of various components within the aircraft systems for comparison with the data recorded during current maintenance. Variations in recorded values may indicate trends that require further investigation’. The QCPM in November 2021 also included notes ‘to look for the deeper root cause of problems if there were frequent or multiple events where recurring maintenance appeared to occur more frequently than expected.
Further, while not related to the investigation findings, Encore reported purchasing a vibration test equipment sensor and mount (previously borrowed for tests), so that it would be readily available, to allow a vibration check to be conducted without delay.
