For many decades, fibre composites have been replacing
traditional aluminium structures in a wide variety of aircraft
types. From the first all-composite kit plane released in 1957,
composites are widespread today in commercial aircraft and many
other aircraft types. This is due to the cost and weight savings
that materials such as glass/phenolic and carbon/epoxy offer
aircraft manufacturers over aluminium, while maintaining or
surpassing its strength and durability.
This study provides an overview of fibre composite use in
aircraft and the issues associated with its use, with a focus on
aircraft operating in Australia that contain these materials. There
are almost 2,000 aircraft on the Australian civil register made of,
or containing, fibre composite materials. This includes most of the
mainline jet fleet, effectively all sailplanes and gliders, many
popular general aviation aircraft, and a third of the growing
amateur-built aircraft category.
There is a lot of conflicting or incorrect information in the
aviation community about the safety and capability of fibre
composite materials. Composite structures behave very differently
under normal loads than equivalent metal structures. Fatigue and
corrosion have been proven through trials of composite repair
patches to be much less prevalent in composites compared with
metals. Subsurface damage such as delamination however can go
undetected for long periods and result in sudden catastrophic
failure. It is important that operators of fibre composite aircraft
be aware of correct detection and repair procedures for the unique
types of damage that occur to composites.
First responders involved in post-crash cleanup operations have
expressed concerns about the long-term effects from exposure to
carbon fibres released from burning composites. Fibre dust can pose
an inhalation risk similar to asbestos. Released fibres or
splinters are needle-sharp, and can cause skin and eye irritation.
In the event of a post-crash fire, smoke and toxic gases are also
released from decomposing composites, presenting further health
risks.