Report from the Aerospace NDT Seminar

Shane Carmody opening the seminar

This was the second time that CASA joined with the NSW Branch of the Institute to provide a seminar for the aerospace industry which was focussed on NDT. Much of the planning and administration was undertaken by Trevor Robinson from CASA. Without his influence and genuine hard work, the profile of the event in Australian aviation circles would have been much less.

Almost 80 registrants from all the states and some from New Zealand and Papua New Guinea. A testimony to the appeal of the meeting.

No less than the deputy CEO of CASA, Shane Carmody opened the proceedings with an acknowledgement of the significance of quality aircraft maintenance to the achievement of a "Safe Skies for Everyone" policy espoused by CASA. He made a point that NDT was a valuable component of aircraft maintenance at all levels of the industry. The large number of professionals gathered at the seminar reflected their dedication to the safety that well conducted NDT brought to aircraft maintenance.

AINDT Federal President Shayne Flynn

Shayne Flynn, the Federal President of the Institute followed Shane Carmody adding his welcome and recognition of the organisational skills of the NSW Branch and CASA which brought about this seminar. And as the first speaker, he remained at the podium to address the audience about the progress and development of the National Aerospace NDT Board. His presentation spanned the inception and early development on to its current position of achieving international recognition of the European Forum for National Aerospace NDT Boards. This achievement is almost unique among such young volunteer industry groups. He also outlined its relationship with CASA and that a new Memorandum of Understanding was being prepared which would further strengthen the relationship and clarify responsibilities. As CASA moves away from a "hands on" regulatory approach to one of devolution to the industry, it will increasingly rely on the Board for guidance and standards in NDT.

Tony Collier followed with a review of the state of NDT in the general aviation (GA) field, He noted the ever increasing size of aircraft now being operated and maintained by GA. 100 seat jet aircraft like the Fokker 100 and BAE 146 were previously only the domain of the airlines but are now being maintained by engineers clearly classified as GA. Tony also described the state of NDT authorised persons with respect to AS 3669 and the CASA Airworthiness Authorites which are held and used by many. Some disparities were identified and raised as issues to be resolved.

Dr. Gary Martin did much to promote the AINDT in his presentation about the various training pathways available to NDT qualification. The in-house approach not having the portability desired by generation Y and X. These younger people have different expectations for their working lives and are attracted by the notion of a transferable qualification. The details of training and examination requirements wer4e also outlined and he found himself on the end of enquires at the coffee breaks. There was a significant proportion of the audience with an interest in NDT training.

Colin Hockings was left with the task of bringing the timetable back on track and did so by keeping to a brisk pace in his presentation on Human Factors and Situational Awareness in NDT. He gave a background to the history of the study of Human Factors, and some of the incidents in aviation safety which focussed attention on the role of human performance, firstly in the management of the cockpit and soon after in other operational areas such as maintenance. The identification of the "Dirty Dozen" developed by the Dupont company was discussed, and their adoption by regulators in as a strategy to raise skills and awareness of this very important topic. The presentation also showed the importance of the development of mental models by those who work in teams. Common mental models are fundamental for a team to reach the same understanding of systems and outcomes, as is good communications a great contributor in reducing human factors problems.

Some of the 75 seminar attendees

Graham Maxwell and Rod Martin brought technology back to the program with timely updates on eddy current phased array and digital radiography. Graham described the development of wide scan probes which are capable of covering large areas in a single pass. The data can then be displayed in traditional displays or plan views with the help of encoders. Whilst the basic technology has been known for some time, it is now becoming commercialised into instruments and equipment offering improvement in inspection performance and cost. The amazing advances in electronic recording media for radiographic images was evident in Rod Martin's presentation. He showed how the use of amorphous silicon flat detectors combined with high energy pulsed x-ray generators could produce film equivalent images. These may be further enhanced using software. The reduction in size of the equipment was dramatic with a full pallet reduced to a couple of suitcases. Studies by Boeing showed that the POD of certain defects using this equipment was better than traditional film methods.

Brian Tydeman from Timken Bearings described a bearing examination system based on the acoustic output from bearings when in motion. A signature profile of bandwidth and amplitude from a defect free bearing can be compared to an in-service bearing. When compared, the source of noise which is outside the normal pattern expected from the bearing, is traceable to various defects such as spalling, corrosion, pitting and other degradation. The extent to which these defects affect the remaining life of the bearing can be reported and the economics of repair or replacement have a more factual basis. The system is similar to other condition monitoring applications where noise generated from plant and equipment is analysed.

One of the most interesting speakers was Dr Phil Anderton who is a vision specialist, and a pilot. He commenced with some physiology of the human eye and then went on to discuss its performance in NDT situations. He was critical of the reliance on the Jaeger charts as these are not satisfactory in the evaluation of a person's sight for the purposes of NDT. Certain conditions such as tunnel vision, early cataract and astigmatism may adversely affect NDT inspections such as penetrant , magnetic particle and radiography, but will not be detected or quantified in any way using the Jaeger charts. The way the eye behaves in conditions of fluorescent inspections was also outlined in some detail. Additionally the rate of blue/green colour blindness runs at about 7% - 8% in the male population, so the presentation of data in colour displays would require consideration of the inspector's state of colour vision. He concluded with some sobering views of eye damage which could have easily been avoided using safety eyeware. This was all done in mostly non-medical language which kept the audience interested.

Derek Hollamby

After lunch, CASA took centre stage, but not before the AINDT took the opportunity to recognise one of the "founding fathers" of aviation NDT, Derek Hollamby. Derek, had a distinguished career in industry and in the Department of Civil Aviation as it was known then, and although in retirement he was very keen to attend and met up with his friends and work colleagues. A presentation of a book about the history of the Boeing Aircraft Company was graciously received albeit with a little embarrassment in front of such a large audience.

John Gratton from CASA offered an insight into the new aviation regulations and how they would affect the conduct of NDT. The new regulations are based on EASA (European Aviation Safety Authority) style outcome based rules, which devolve responsibility to the industry. Where previously CASA was prescriptive in their communications with industry, in future they would communicate what outcome was required and allow the industry to determine the best way to achieve that outcome which would be acceptable to CASA. Documents known as Acceptable Means of Compliance (AMC) would give guidance but not be the only way to show compliance. This flexibility is expected to generate improved productivity and less duplication in achieving an acceptable level of safe aircraft operations. The amount of procedural documentation should also be reduced.

Trevor Robinson followed John with a brief review of the progress in replacing the old CAO 108.8 and 108.10 which describe penetrant and magnetic particle testing. CASA in conjunction with the NANDTB is preparing inspection guidelines which are designed to be used in aviation maintenance when there is no data prescribed by the aircraft or component manufacturer. This work is expected to be completed soon and will result in the removal of other out of date instructions as well.

The seminar finished on a high note with an excellent presentation by Steve Swift on the interrelationship of NDT and damage tolerance principles. Steve was awarded the Sir Frank Whittle Safety Award by the Federation of Airworthiness for his work in education. The "Diamond" model of inspection evaluation he has developed shows a structured approach to assessing the effectiveness of inspection techniques. He commences with defect factors such as size and location, then applies fracture mechanics to the develop a failure mode. From this the operational influences are considered and an inspection plan can be developed which ensures the detection of the defect before it grows to a size which will cause an in-service failure. He also noted the reliance on engineers to liase and include NDT specialists in the development and evaluation of aircraft inspections.

The final session was a Q&A with a panel of specialists and produced some lively interchanges. On reflection, this was a great opportunity taken by those who attended to renew contacts, ask questions and remain in, or rejoin the mainstream of NDT practice in aerospace.