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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.
A Numerical Investigation into the Crashworthiness of Automotive Child Restraints in Transport Category Aircraft
RMIT undertook a research project under the sponsorship of CASA with the objective of developing a better understanding of the crashworthiness of automotive child restraint systems (CRS) in transport category aircraft under emergency landing dynamic conditions. Three different CRS installation methods were considered: the aircraft seat lap belt, the European ISOFIX system, and the North American LATCH system. Typical airline economy class seating configurations involving forward-facing CRS installed by each of these methods were evaluated in terms of the level of protection offered to the CRS occupant, the injury potential for a passenger seated directly aft of the CRS, and the effect of the CRS on aircraft seat loading and dynamic behaviour.
Prior research projects carried out by CASA into child restraint were used as the basis for the development and validation of a computer model that was used to carry out experiments in a virtual environment. This method allowed many seat configuration parameters to be analysed simultaneously and also allowed the analysis of some parameters which were unable to be measured by physical testing.
An Investigation of Automotive Child Restraint Installation Methods in Transport Category Aircraft - Phase II
This research continues the investigation into the dynamic performance of automotive child restraints when fitted to an economy class airline seat. It compares the performance of child restraints when attached by ISOfix, LATCH and lap belt installation methods, a child in their own airline seat, and lap held infants restrained by a Supplementary Loop Belt. The testing also gathered data for Lower Anchorages design standards that will be required by the ISOfix and LATCH attachment methods. Additionally, the testing investigated injury levels to an adult seated in the row behind an Automotive Child Restraint.
First Diamond
A paper presented at the International Committee on Aeronautical Fatigue's 25th Symposium, Rotterdam, The Netherlands, May 2009. In this third paper in his 'diamond' series, Steve Swift reviews how to set the 'threshold' for a structural inspection program. He shows how 'damage tolerance' and the 'diamond' work the same as for any other interval, and how they would work even better with risk management, human factors and less prescriptive regulation. The pages do not fill an A4 page, and their numbering does not start at 1, because the paper is an extract from the published proceedings. Please note the copyright at the bottom of the first page.
Read First Diamond (1.1 Mb)
A Collective Approach to Aircraft Structural Maintenance Programs
A paper presented to the International Air Safety Seminar (IASS) 2008 in Honolulu, Hawaii, October 2008. Steve Swift considers three divisions in the way we design, implement and regulate aircraft structural maintenance programs. They hinder safety and economy. He offers suggestions for airworthiness authorities, aircraft manufacturers and airlines.
Read A Collective Approach to Aircraft Structural Maintenance Programs (258 Kb)
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.
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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.
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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)