Bob Kells and his investigation team had arrived at the accident site by helicopter. It had been at least a day since the Twin Otter had struck trees nine kilometres south west of Simbai in the Bismark Ranges, Papua New Guinea, when the crew had tried to fly it out of a steep valley.
It was an incredible sight. The fuselage was intact. The wings had been taken off by the trees. Ahead of it was a precipice -- a steep drop from which there may have been no survivors had the aircraft gone over.
It was a unique situation. Bob had been able to interview the crew in hospital and they talked openly about what had happened. He had been on standby within hours of the crash as the civilian leader of a joint civil/military team of investigators. The army operated the aircraft but as it was a civil registered aircraft, the accident investigation fell under the jurisdiction of the PNG authorities. They had requested that the (then) Bureau of Air Safety Investigation conduct the investigation.
That was in November 1997. The final investigation report, number 9703719, was released to the public in June 1999. In that period, action had been taken on a series of recommendations that had highlighted significant deficiencies in the way the military had conducted tropical mountainous flying training in Papua New Guinea.
What types of lessons are learnt from investigations like this? What did this one teach the aviation industry?
According to Dr Rob Lee, Director, Human Factors, Systems Safety and Communications, if underlying organisational deficiencies are left unchanged, the same kinds of occurrences would continue to happen.
In the report, the crew of the Twin Otter was found to have been operating within an organisational environment that had a 'low level of experience and corporate knowledge regarding the operations of fixed-wing aircraft...in tropical mountainous areas'.
'Against this background, deficiencies were identified in the planning and preparation for the exercise, including risk assessment and the selection and briefing of the training pilot,' so the report states.
Aviation safety across the world relies on the thoroughness of accident and incident investigations and the timely reporting of the findings. Dr Assad Kotaite, President of the International Civil Aviation Organization (ICAO) said, 'Without this essential information the efforts of industry, aviation administrations and the ICAO cannot be effective in addressing hazards in the air transport system.'
Since the 1950's Australia has had one of the world's most comprehensive aviation occurrence reporting systems. By law, anything that affects the safety of flight must be reported.
Under Annex 13 of the ICAO Standards and Recommended Practices, Aircraft Accident and Incident Investigation, a mandatory reporting system must be in place and supported by a non-punitive voluntary system.
In 1988, Australia's mandatory open reporting system was complemented by the Confidential Aviation Incident Reporting system (CAIR), where the reporter's identity remains confidential. Through both systems, the ATSB receives thousands of reports annually.
Most of these reports are of a relatively minor nature. "In the mandatory reporting system we get around about 5,000 incidents and about 3-400 incidents through the confidential system," Dr Lee said.
"One of the features of the Australian system, unlike say in the US where you only have to report certain categories of more serious incidents, is that the information from relatively minor occurrences can be analysed to see if there is an underlying reason that might be causing the occurrences," Dr Lee said.
In 1996 the Bureau reviewed the way it stored and collected air safety occurrence information. The Systemic Incident Analysis Model (SIAM) was developed and provided a better way of using occurrence data. It is based on the model developed by Professor James Reason of the University of Manchester, who developed a conceptual and theoretical approach to the safety of large, complex sociotechnical systems such as aviation.
Major investigations such as the PA-31 accident at Young (1993) the Boeing 747 accident at Sydney airport (1994) and the Class G airspace demonstration (1999) were undertaken and reported using the principles of the Reason model.
These investigations all had substantial impacts on rectifying major latent organisational deficiencies in the aviation system across government, corporate, regulatory and organisational areas.
According to Dr Lee, if these investigations had not been undertaken in accordance with the basic principles of the Reason model, the significant systemic safety outcomes would not have been achieved.
What safety lessons would be lost if there was no reporting culture?
A great many issues have been identified by the analysis of reports received through Australia's incident reporting systems. Numerous lessons have been learnt and actions taken as the following CAIR report from mid-1999 shows.
On taxi, we noted traffic of a C310 approaching the circuit and a C182 departing. Upon runway entry and TCAS switching to T/A R/A, we had indication of one aircraft only, which we identified as the C310. We then asked the C182 if it was transponder equipped and, if so, to switch it on. The reply was that they were equipped and that they would switch it on. It appeared to me that they hadn't forgotten to switch it on, but rather that they were unaware of the requirement to have it switched on. We subsequently got a return and used it to assist our separation procedures.
My view is that far too many aircraft are not using their transponders correctly. These are predominantly low hour or OCTA only pilots. I believe that having the relevant transponder operating procedures within the 'Radar Services and Procedures' section (both CASA and JEPPS) is misleading and results in this information being missed by pilots who never operate in a radar environment. I feel this information should be in the OCTA procedures section as well.
Response from Airservices
The use of transponders is clearly defined and adequately covered in AIP ENR 1.6 - Radar Services and Procedures - under Section 8. However, AIP Book A/L 26, effective 2 Dec 99, has a new section in ENR 1.1 which was submitted by CASA. The new section advice is as follows:
- Pilots of aircraft fitted with a serviceable Mode 3A transponder must activate the transponder at all times during flight in non-controlled airspace, and if the transponder is Mode 3C capable, that mode must also be operated continuously.
- For further information on the operation of transponders, including normal and emergency codes, see ENR 1.6 Section 8.
"Reporting systems serve as a vital early warning device so it is important that people feel able to lodge a report on anything that they think is affecting safety (see table 2). New methods of analysing the information, such as the Systemic Incident Analysis Model (see Flight Safety March-April) demonstrate the operational value of a reporting culture. We have to know about problems before lives are lost," Dr Lee said.
A sound reporting culture is one of the best defences against that happening.
|Type:||Educational Fact Sheet|
|Publication date:||13 May 1999|