A fatal Robinson R44 helicopter accident has prompted the ATSB to recommend safety improvements to helicopter fuel tanks in the United States and Europe.

Four people died in the March 2013 accident at Bulli Tops in New South Wales. The R44 helicopter they were travelling in was engulfed in fire after striking a tree and hitting the ground.

Following this accident, Australia's Civil Aviation Safety Authority, and other international regulators, made it mandatory for R44 helicopter operators to replace the R44's all-aluminium fuel tank with a bladder-type fuel tank.

ATSB Chief Commissioner Martin Dolan said that bladder-type fuel tanks reduce the risk of post‑impact fire in the R44. But the ATSB remains concerned at the risk of post-impact fire in helicopters not fitted with crash-resistant fuel systems.

'We believe the US Federal Aviation Administration (FAA) and the European Aviation Safety Agency (EASA) can help improve the safety of many helicopter pilots and their passengers,' Mr Dolan said.

'We have issued safety recommendations to the FAA and EASA. We ask them to take action to increase the number of crash-resistant fuel systems fitted to existing and newly-manufactured helicopters.

'Under international convention, we would expect to hear from the FAA and EASA about their proposed responses to these recommendations by early September 2015,' Mr Dolan said.

The Bulli Tops accident was similar to other R44 accidents involving fatal post-impact fire that made survivability impossible. In each case, the R44s were fitted with all-aluminium fuel tanks.

Mr Dolan said, 'Statistical analysis of accidents in Australia and the United States over ten years found a higher proportion of post-impact fires involving R44s than for other similar helicopter types.'

The analysis also identified that, despite a 20-year-old requirement for new helicopters to have a crash-resistant fuel system, several helicopter types are being made without such a system. In addition, although modification kits are available for a number of helicopter types, they have not been incorporated in many of the existing civil helicopter fleet.

Read the report: Collision with terrain involving Robinson R44 helicopter, VH-HWQ, at Bulli Tops, near Wollongong, New South Wales, on 21 March 2013

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