The Australian Transport Safety Bureau (ATSB) today released its second interim report into an incident involving a Virgin Australia Regional Airlines ATR 72 aircraft near Sydney on 20 February 2014.
During a flight from Canberra to Sydney, the aircraft sustained a 'pitch disconnect' while descending into Sydney. The pitch disconnect occurred when the two flight crew attempted to slow the aircraft down and inadvertently applied opposing control inputs (one pilot pushed the control at the same time the other pilot pulled), and resulted in significant damage to the aircraft's tail structure.
ATSB Chief Commissioner Greg Hood said that as a result of extensive investigation and aeronautical engineering analysis of the incident, the ATSB has issued safety recommendations to the aircraft manufacturer (ATR), the European aviation safety regulator (EASA) and Australia's aviation safety regulator (CASA).
"The ATSB released its first interim report into this incident in July last year. That report identified a significant safety issue relating to the strength of the aircraft's tail structure in the event of a pitch disconnect," Mr Hood says.
"Our concern is that, given the design of the ATR42 and ATR72 aircraft, opposing control inputs can result in aerodynamic loads that may exceed the design strength of the tail structure, causing significant damage."
"Since we identified this issue, our aeronautical and structural engineers have conducted extensive analysis based on additional data provided by ATR. The findings of that analysis, supported by an independent peer review from the UK Air Accidents Investigation Branch, confirmed our initial concerns."
"The ATSB welcomes the engagement with the European and Australian regulators EASA and CASA, and the safety action taken by the manufacturer ATR, who continues to conduct further engineering analysis of the issues identified by the ATSB."
Mr Hood also welcomed the actions taken by the two Australian operators, Virgin Australia and Toll Aviation, to reduce the potential for a recurrence of this event as well as to manage the risk of adverse outcomes should such an event occur.
"Given ATSB's level of concern as to whether the aircraft has sufficient strength to withstand the loads resulting from a pitch disconnect, and as a result of our investigation to date, we have recommended that:
- ATR complete an assessment of the safety issue as soon as possible to determine if the aircraft can safely withstand the aerodynamic loads from a pitch disconnect
- EASA monitor and review ATR's engineering assessment and take immediate action if the analysis identifies that the aircraft does not have sufficient strength
- CASA review ATR's engineering assessment and take immediate action if the analysis identifies that the aircraft does not have sufficient strength."
Under legislation, ATR, EASA and CASA have 90 days to respond to the ATSB's safety recommendations.
The ATSB has and will continue to work closely with ATR, EASA, CASA and the Australian operators of these aircraft throughout the remainder of this investigation and will immediately bring any additional safety issues that may be identified to their attention.
This press release should be read in conjunction with the second interim report and explanatory statement available on the ATSB website at AO-2014-032.