Technical Papers
The papers below are for those wanting background information on airworthiness topics. They are not necessarily current and do not necessarily reflect CASA policy.
An Investigation of Automotive Child Restraint Installation Methods in Transport Category Aircraft
A research report into the dynamic performance of automotive child restraints when fitted to an economy class airline seat. There was specific focus on the top tether contribution to dynamic performance as typically configured by airlines in Australia. Additionally, it compares this performance of current Australian infant restraints to ISOfix type infant restraints. ISOfix restraints don't use the car/aircraft seat belt for retention, but rather a steel link that latches to a mating fitting in the seat bight. ISOfix type restraints are due to be included in the Australian Standard for Automotive infant restraints (AS/NZS 1754) in 2008.
Read An Investigation of Automotive Child Restraint Installation Methods in Transport Category Aircraft (2.2 Mb)
Some Observations on Fatigue Life Management
A paper presented to the 5th International Conference on Structural Airworthiness of New and Aging Aircraft, Hamburg, Germany, June 1993 (the proceedings published as DGLR-Bericht 93-02). Alan Emmerson, former Manager, Maintenance and Durability, describes the main methods of fatigue life management, including some of their less well recognised implications.
Read Some Observations on Fatigue Life Management (590 Kb)
A Perspective on the Use of NDT in the Inspection of Aging Aircraft
A paper presented to the Aging Commuter Aircraft Conference, Canberra, August 1992. An NDT inspector with forty years experience cautions 'damage tolerance' proponents about their increasing reliance on NDT to manage structural fatigue in aging aircraft.
Read A Perspective on the Use of NDT in the Inspection of Aging Aircraft (580 Kb)
Rough Diamond
A paper presented to the International Committee on Aeronautical Fatigue's 23rd Symposium, Hamburg, Germany, June 2005. Two regulators review whether “damage tolerance” is delivering the safety envisioned when it became the preferred fatigue management method for large civil airliners. They laud the method, which they call the “diamond”. It is more valuable and versatile than first thought. It was a breakthrough. However, they find it so cluttered and poorly regulated that many reject it and others misuse it. The diamond is “rough”. They recommend “cutting and polishing”, by simplifying the diamond and its rules.
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Rusty Diamond
A paper presented at the International Committee on Aeronautical Fatigue's 24th Symposium, Naples, Italy, May 2007. Steve Swift reviews if ‘damage tolerance’ could be as useful for corrosion as it is for fatigue. The answer is 'yes'. Operators, manufacturers and regulators could save time, money and lives. Examples, recommendations and draft regulatory guidance show how.
Read Rusty Diamond (614 Kb)
Big Challenges for Little Airliners
A paper presented to the 10th Australian International Aerospace Congress, Brisbane, July 2003. This paper looks at several challenges facing the structural safety of "little airliners" in Australia. They include high usage, inappropriate design standards, inadequate maintenance programs and dwindling technical support. It considers some possible solutions, concentrating on better standards for type certificate holders, modifiers, repairers and maintenance programs. Critical to their effectiveness will be a high level of international cooperation.
Read Big Challenges for Little Airliner (1 Mb)
Gnats and Camels
A paper presented to the International Committee on Aeronautical Fatigue's 20th Symposium, Seattle, USA, July 1999. This paper reviews thirty years of regulating structural fatigue in light aircraft from an Australian perspective. Australia has one of the world’s largest and hardest-working fleets. Australia’s regulator (CASA) has been an active international participant. The paper looks at the history and effectiveness of FAR 23.572, and the issues and controversies along the way. Undoubtedly safety has improved. Wings and things still break, but less often. Suggestions for further improvement include better targeting of regulatory effort and more international cooperation. We still have much to learn. We can only assess the effectiveness of new policies and methods by revisiting them after ten, twenty or thirty years service experience.
Technical Paper (386 Kb)
Aero Commander Chronicle
A paper presented to the International Committee on Aeronautical Fatigue's 18th Symposium, Melbourne, May 1995. The service history of the Aero Commander light twins teaches a hard lesson in the theory and practice of fatigue control.
Read Aero Commander Chronicle (381 Kb)