"How Old is Too Old? The impact of ageing aircraft on aviation safety

The purpose of this report was to examine the relationship between ageing aircraft and flight safety, to determine the chronological age of the Australian aircraft fleet, and to review current and future directions for the management of ageing aircraft.

Age can be managed by retiring the aircraft and purchasing a newer aircraft or through adequately maintaining ageing aircraft through additional and specific maintenance. This requires cooperation between regulators, manufactures, maintainers, operators, and owners. Continuing airworthiness programmes and Supplementary Inspection Programmes are methods of ensuring adequate maintenance. Ageing of an aircraft can be a safety issue, but with adequate maintenance, the consequences of ageing can be mitigated. Current and future maintenance programmes will act as a preventative measure to reduce the safety risk associated with ageing aircraft, but only if the operators adhere to the programmes.

In Australia, the average age of fleet of turbofan aircraft is low, and has been is decreasing. Multi-engine turbofan aircraft with a maximum take-off weight between 50,001 and 100,000 kg had the lowest average age in 2005 at just 6 years. This was the only aircraft category whose average age decreased over the period 1995 to 2005. The turbofan aircraft with a maximum take-off weight of more than 100,000 kg had an average age of 11 years in 2005. The high-capacity turbofan aircraft receive extensive continuing airworthiness support from the manufacturers. The low age and extensive continuing airworthiness support provide a double defence to ensure the safety of the Australian multi-engine turbofan aircraft fleet.

The piston engine fixed-wing aircraft fleet, by contrast, had the highest average age at 30 years. These aircraft often do not receive the same level of continuing airworthiness support from the manufacturer as the turbofan aircraft. In Australia, multi-engine piston aircraft are often used in regular public transport and charter operations, and therefore the high average age needs to be considered in relation to their safe operation in passenger services.

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