Accidents involving Robinson R44 helicopters without bladder-type tanks fitted result in a significantly higher proportion of post-impact fires than for other similar helicopter types. In addition, the existing United States regulatory arrangements are not sufficient to ensure all R44 operators and owners comply with the manufacturer's Service Bulletin SB-78B and fit these tanks to improve resistance to post-impact fuel leaks.
Although certification requirements for helicopters to include a crash-resistant fuel system (CRFS) were introduced in 1994, several helicopter types certified before these requirements became applicable are still being manufactured without a CRFS.
Many of the existing civil helicopter fleet are not fitted with a crash-resistant fuel system, or do not have an equivalent level of safety associated with post-impact fire prevention.
There was no Track Stability Management Plan in place for the section of track where the buckle developed – as was required by the ARTC’s CoP.
V/Line’s organisational processes for responding to and rectifying rail creep defects did not ensure that all such defects were addressed in a timely way.
While the design of the on-load release system allowed the reset position of the hook to be visually confirmed, it did not allow for visual confirmation that the release segment and mechanism had been correctly reset. Consequently, the hook device could appear to be properly reset when it was not.
The manufacturer’s calculations did not take into account the shock load imposed on the simulation wires or the lifeboat and launching frame mounting points.
The Recognized Organization’s process for the approval of the simulation wires for ‘maintenance and testing’ had not taken into account the shock loading that would be experienced during testing.
An equivalent, alternative arrangement to the safety pin had not been provided to prevent inadvertent tripping of the freefall lifeboat’s on-load release during routine operations, such as inspections and maintenance.
Contract documentation and specifications within the Services and Supply Umbrella Agreement were generic and did not adequately specify the intended purpose of the type 37 turnout.
The VCA type 37 turnout design and V/Line’s provisional type approval process did not fully identify the subtle design changes inherent with the VCA type 37 turnout in determining testing, commissioning and validation needs.
The physical testing and commissioning regime for the VCA type 37 turnout did not require the use of standard gauge trains with 127 mm rimmed wheels.
The design of the VCA type 37 mixed gauge turnouts (MYD882 and MYD887) was such that they were not suitable for use by rolling stock with a 127 mm rimmed wheel.
Inherent to the design of many dual gauge turnouts, is a region of reduced wheel rim contact on the broad gauge switch blade (rail head) through the transfer area. In circumstances where the switch blade is insufficiently restrained, and where the passing train has a narrow (127 mm) wheel rim width, there is an increased risk of derailment.
V/Line’s processes for responding to the report by the driver of train ST21 did not limit or prevent the subsequent movement of train ST24 before checks had been carried out to identify and assess any potential track and/or rolling stock issue(s).
The ultrasonic testing regime was not effective in consistently identifying corrosion and wasting of the rail web at unsealed level crossings.
The track inspection regime did not identify the deteriorated rail condition at the O’Tooles Road level crossing. The regime placed an over-reliance on ultrasonic testing and did not include sufficient supplementary systems for monitoring the condition of buried track at unsealed level crossings.
The method of constructing crossings at unsealed roads heightened the potential for corrosion and track degradation and limited the opportunity for effective visual inspection. The network standard for crossing construction did not directly address the particular challenges of unsealed roads.
GWA had no documented system in place to assess the suitability of second-hand components for re-use.
The frequency of driver reporting and locomotive cab rides by track inspectors had been insufficient for identifying rough track through the derailment site.
