Taipan Crash Investigation – Questions Asked.
Officially, the cause of the ditching of a Taipan helicopter with ten people on board on March 22 is still being investigated. Unofficially, details have emerged suggesting the cause is likely to be the failure of Army to implement a fleet-wide software fix to the problem, which first emerged in 2010.
The fundamentals of the accident are known – a night flight that was part of a Special Forces training exercise. While over Jervis Bay the helicopter experienced an engine failure while at low altitude and the pilot carried out what has been called a textbook response, deploying the emergency floatation system, and landing the Taipan on the surface of the sea. This enabled all on board to evacuate safely.
Engine failure on a Taipan is very rare. Each helicopter has two RTM322 Rolls Royce Turbomecca powerplants that are in widespread use not only on the 500 members of the Taipan family, but also on Augusta Westland AW101 transport helicopters and the U.K. Apache fleet – amongst others.
As reliable as they are, in April 2010 a Taipan experienced an engine failure while flying near Adelaide. It was able to return and land at RAAF Base Edinburgh on one engine, but this caused the entire fleet to be grounded for more than three months while an investigation took place. It transpired that the problem was not with the engine itself but rather around the process of restarting it during a mission.
Helicopter turboshaft engines are not meant to be switched on and off repeatedly during an operation. Ideally, you power them up at the start and shut them down at the end – and any idling that might be required in between does not use a huge amount of fuel.
Unfortunately, this had not been communicated to Australian Army pilots – or at least not in the 2010 case – and the helicopter had been subjected to a “hot start” a short time before the in-flight failure. Heat causes metal components to expand at different rates and what had occurred in this case was that moving parts rubbed against each other when they were not meant to, damaging bearings and seals.
This would not have happened if the engines had been allowed to cool down in between missions or if a different process had been followed for their restart, or if they had been running continuously.
By July 2010 the prime contractor Airbus Helicopters and Safran – the corporate parent of the engine – had developed a software fix that would make it impossible for a pilot to incorrectly perform a “hot start.” The Taipan is a complex helicopter with a modern fly-by-wire flight control system using multiple computers, and having the latest software is a vital ingredient for their performance.
This means that software updates are a regular part of supporting the Taipan fleet – but bizarrely Army only agreed to the engine fix being applied to an initial small number of helicopters, apparently because of concerns about the cost.
Engine failure in flight is an extremely serious event, putting the lives of all on board at risk. The 2010 software fix should have been applied to all 47 Australian helicopters, irrespective of how much money was involved. At the very least this should have been done for reasons of commonality – it’s a problem waiting to happen if pilots believe they are flying one version of a helicopter when it turns out that they are at the controls of something different.
It seems highly probable that the Taipan forced to ditch into Jervis Bay had not received the vital software update that should have been installed a decade ago. It is understood that it underwent just such a “hot start” prior to the ditching. Thanks to its emergency floatation system not only was everyone able to get out, but the helicopter itself was towed to a beach – to the delight of the media – fuelling more stories about the unreliability of the Taipan fleet, with pictures to match.
The Blackhawk helicopters being purchased to replace them do not have emergency floatation systems and if they ditch, they quickly sink.
Another perversity in the Australian system is that the performance-based logistics contract imposed on Airbus means that Defence makes money every time a helicopter is grounded. This gives the customer a financial incentive to keep the helicopters on the tarmac because penalties kick in for every flight hour that has been lost.
Combined with inherent problems in Army logistic systems and a failure to retain experienced mechanics, a picture emerges that is completely at odds with the common view that there is something inherently wrong with the helicopters.
This reputational damage has resulted in ridiculous events such as flights being stopped while Army investigated the use of cadmium for the helicopter’s external hook. Cadmium is a metal in widespread use throughout military and commercial aviation and in solid form poses no risk to humans whatsoever. Despite this, Army insisted on the construction of a unique cadmium-free hook.
By this and other devices – such as simply not ordering enough spare parts – Army has been able to drive up the cost per flight hour of the Taipan fleet either deliberately or through error to truly astronomical levels. These inflated costs have provided the justification for retiring the entire fleet about 20 years ahead of schedule.
This is not to say that the Taipans have been trouble free. They have not been, especially in their early years – but this is quite common with modern, complex platforms. As APDR has frequently reported, most international customers have been happy with their fleets – though Norway is trying to return theirs, with Sweden and Belgium possibly in the same boat. The majority of users, including France, Germany and Italy have not experienced abnormal difficulties.
Let’s hope that the findings of the current investigation are made public – but don’t hold your breath. Army has form in this regard – in 2016 Defence organised an independent review into the reliability of the Taipan and Tiger fleets. Known as the Houston Review, it is believed to have been critical of Army processes because its findings were instantly classified and have been buried ever since.
Only a handful of people have ever seen the document and if Army has its way it will be hidden forever. It seems that nothing will be allowed to deflect the $11 billion process of replacing Taipan and Tiger with older-generation U.S. helicopters.
An outline of this story was provided to Defence more than a week ago in the hope of receiving answers to several questions. After deadline, the following official response was received:
“The investigation into the MRH90 ditching is ongoing.”
