The Civil Aviation Safety Authority (CASA) last week presented data to the Senate Standing Committee on Rural and Regional Affairs and Transport (RRAT) that it says supports its claim that community services flights are a greater risk than regular private flights.
According to the data tabled, for the period 2008-2017 there were four community service flights (CSF) that resulted in accidents from a total of 17,750 flight hours, resulting in an accident rate per 10,000 hours of 2.25.
The figures for private, business and sport aviation across the same period show 537 accidents in 3.5 million hours, a rate of 1.53 per 10,000 hours.
"[CASA] has compared Community Service Flight (CSF) data with that for the private and business flying sector using material from the Bureau of Infrastructure, Transport and Regional Economics (BITRE) and the Australian Transport Safety Bureau (ATSB)," CASA said in its reponse to a question from the Centre Alliance's Senator Rex Patrick.
"CASA has undertaken this analysis separate to the ATSB investigation process. The data and analysis is not derived from the ATSB investigation [ATSB investigation AO-2017-069], which is still in draft. The greater accident rate of CSF raises the issue of managing the safe operation of these flights that may carry passengers unaware of the apparent elevated risk.
"Assessment of the accident and incident rates for CSF and private/business/sports (excluding gliding) over the past 10 years (2008 to 2017) indicates:
- the CSF accident rate is 1.5 times higher than that for private/business/sports
- the CSF fatal accident rate is 5.4 times that for private/business/sports."
Angel Flight CEO Marjorie Pagani has disputed CASA's statistical analysis.
"CASA has relied on BITRE data," Pagani told Australian Flying. "They didn’t start collecting CSF data until 2014, with no definition as to what that meant. CASA defined that term only this year.
"In the three years they rely upon (2015-17) there were only an average of 46 respondents to the [BITRE] survey. In those years alone we averaged 273 aircraft being active for us. We have given all our flight numbers to CASA and updated them several times.
"We have also sworn to them in our affidavit in court."
Angel Flight is disputing the veracity of the CASA analysis on several grounds, one of which is the total number of flying hours used to arrived at the risk rate.
"They [CASA] know we have done 46,000 flights," Pagani said. "To attribute to us 17,500 hours over nine years is laughable ... clearly done to fudge the figures."
Angel Flight's statistical analysis found that there is no significant difference statistically between fatal accidents in CSFs and regular private flights. However, it does concede that there is a significant variation in all accidents, but cautions against interpreting the data as meaning that Angel Flight is more unsafe because it doesn't take into account the context.
The statisticians that compiled the analysis also found that the CASA data includes a mis-match in time period between the CSF and the regular private flight figures, which may potentially put the conclusions in error.
Angel Flight has indicated that they will progress legal action to have CASA's new CSF regulations struck out, and the new rules are still subject to disallowance motions in both the Senate and the House of Representatives. However, these motions will have to be resubmitted in the new parliament.