Continuing airworthiness is fundamental to the safe operation of Part 135 non-scheduled passenger operations. Operators within this sector often operate their aircraft to regional and remote locations with limited access to:
- maintenance facilities
- engineering support
- replacement components.
Maintaining aircraft in an airworthy condition requires:
- effective maintenance planning
- timely defect management
- close collaboration between:
- operators
- maintainers
- continuing airworthiness management personnel.
Safety data supports the importance of this issue. Technical defects, precautionary returns and landing gear indication events are among the most frequently reported occurrence categories within the Part 135 sector.
Discussions focused on four recurring challenges:
- supply chain delays affecting the availability of aircraft parts
- limited engineering support in regional and remote locations
- poor quality exchange components
- ageing aircraft fleets.
During the regulatory bowtie review, participants also noted additional maintenance-related threats, including:
- increased reliance on defect deferral processes
- limited defect reporting
- the impacts of supply chain disruptions.
These issues may influence:
- aircraft availability
- maintenance scheduling
- decision-making.
Maintenance-related risks extend beyond the completion of scheduled inspections. Operators must also manage the continuing airworthiness of their aircraft throughout their operational life, including the:
- timely finding and rectification of defects
- availability of approved replacement parts
- maintenance of accurate technical records.
Regional and remote operations can present additional challenges. Aerodromes may have limited access to qualified maintenance personnel, requiring operators to carefully coordinate maintenance activities and consider the impact of aircraft downtime. Delays in obtaining approved replacement components may also increase pressure on maintenance planning and aircraft availability.
Workshop participants highlighted concerns regarding the quality of some exchange components and the increasing age of many aircraft operating within the sector. Older aircraft may require increased attention to:
- corrosion
- fatigue
- wiring degradation
- component reliability.
While ageing alone does not make an aircraft unsafe, it reinforces the importance of effective maintenance programmes, proactive defect reporting and continuing airworthiness oversight.
What you can do
Operators can strengthen continuing airworthiness by embedding maintenance risk management within their Safety Management System and day-to-day processes. Practical strategies include:
- ensuring they plan and complete maintenance in accordance with approved maintenance data and regulatory requirements
- maintaining complete, accurate and up-to-date aircraft maintenance records
- encouraging prompt reporting of defects, abnormal aircraft behaviour and recurring technical issues
- monitoring recurring defects to find emerging reliability trends
- considering supply chain risks when planning scheduled maintenance and major component replacement
- verifying the suitability and traceability of replacement components before installation
- working closely with continuing airworthiness management personnel and maintenance organisations to support effective maintenance planning
- considering additional inspections where experience finds emerging risks associated with ageing aircraft
- incorporating maintenance-related hazards into the operator's Safety Management System and risk assessment processes
- reviewing deferred defects to ensure they remain appropriately managed and do not introduce unacceptable risk
- promoting effective communication between flight crew, maintenance personnel and management to support timely finding and resolution of technical issues.
What we have done
We continue to support continuing airworthiness through regulatory oversight, surveillance, education and industry engagement.
Current activities include:
- providing guidance material supporting continuing airworthiness and maintenance compliance
- conducting surveillance of approved maintenance organisations and air transport operators
- monitoring occurrence data and defect trends to find emerging safety issues
- working collaboratively with industry to promote effective maintenance practices and continuing airworthiness management
- supporting the reporting and analysis of technical defects to improve sector-wide safety intelligence
- incorporating maintenance-related safety information into education, surveillance planning and regulatory risk analysis activities.
We also continue to work with industry to support the safe management of ageing aircraft, maintenance quality and engineering capability. This is because we recognise the important role these activities play in maintaining the safety and reliability of Australia's Part 135 fleet.