Leonardo Helicopters could face legal action over the fatal crash of an AW169 in the UK due to a tail rotor failure.

In its final report into the 27 October 2018 fatal crash, the UK Air Accidents Investigation Branch (AAIB) pinned the cause of the accident on the seizure of a critical bearing in the tail rotor control system.

Leicester City AW169 crash animation-c-AAIB

Source: AAIB

AW169 came down outside of Leicester City football stadium

However, the AAIB investigation details multiple regulatory failings which it says created the conditions for the crash; it has issued multiple safety recommendations only to the European Union Aviation Safety Agency (EASA) rather than the helicopter manufacturer.

But law firm Stewarts, which is acting for the families of three of the five people that died in the crash – the then owner of Leicester City Football Club Vichai Srivaddhanaprabha, pilot Eric Swaffer and his partner and fellow aviator Izabela Lechowicz – say Leonardo Helicopters should be held accountable.

Peter Neenan, a partner in the aviation team at Stewarts, says the AAIB report is a “frightening tale of missed opportunities” and that the AW169 was “an accident waiting to happen”.

Stewarts argues that the airframer failed to “implement sufficient mitigation measures within the wider tail rotor control system” that would have avoided a “catastrophic loss of control” from the bearing failure.

“Some of those measures would have been as simple as changing the thread direction on component parts, a measure that they had already implemented on an earlier helicopter, the AW139,” says Neenan.

A left-hand thread on a nut securing the tail rotor control shaft to the actuator lever mechanism would likely have prevented the two parts becoming separated once the duplex bearing supporting the shaft failed; Leonardo has since implemented that change on a new version of the assembly.

Leonardo Helicopters had identified the seizure of the duplex bearing as potentially “catastrophic”, believing it would cause the control shaft to fracture as torque from the drive system was transferred to it, ultimately leading to a loss of tail rotor control.

But EASA regulations state that “once the system safety assessment identifies the failure of a component as catastrophic, then there is no requirement for the manufacturer to consider the associated implications of that failure”, the AAIB report notes.

Stewarts also points to other issues identified in the report as evidence that Leonardo Helicopters’ actions contributed to the crash.

These include a failure to share flight-load test data with the bearing manufacturer to validate the component’s suitability for the application. It also had no system in place to inspect and analyse bearings removed from in-service helicopters.

But EASA regulations did not require the manufacturer to take such actions, the AAIB report states.

Aiyawatt Srivaddhanaprabha adds: “I am deeply saddened by the course of events. Almost five years after my father’s passing, this report provides concerning evidence against Leonardo.

“My father trusted that he had bought a safe helicopter from a world-renowned manufacturer. Had he known what we know now he would never have risked his life in this machine.”

Vichai Srivaddhanaprabha’s family “are now considering their legal recourse against Leonardo”, says Stewarts, noting that litigation has already been commenced in Italy – the home of the airframer and the AW169 production line – on behalf of the families of Swaffer and Lechowicz.

Leonardo Helicopters says it extends its “sincere sympathies and deepest condolences to all those affected by this tragedy and in particular to the families and loved ones of those who lost their lives”.

But the airframer says the AAIB did not direct any safety recommendations at Leonardo Helicopters, adding: “The AAIB final report rightly concludes that Leonardo complied with all regulatory requirements in both the design and manufacture of the AW169.

“The final report also recognises that Leonardo’s immediate actions after the accident, such as the implementation of additional safety checks, which were later adopted by EASA… have ensured that the global fleet of AW169s have continued to operate safely.”

Additionally, Leonardo Helicopters points to a letter from itself, Italy’s ANSV civil aviation regulator, and EASA, contained within an appendix to the main report, that disagrees with several of the AAIB’s findings, hypotheses and methodology.

These include the AAIB’s conclusions about the likely cause of the bearing failure and the potential for certain manoeuvres to generate unexpectedly high loading of the bearing; such a theory “seems very debatable”, it says.

Any conclusion about the lack of a reporting and inspection regime is also flawed, the letter says, noting that at 1 November 2018 none of the in-service fleet had reached 2,400 flight hours – the point at which the duplex bearing was supposed to be replaced, it says.

Defects found causing the “premature” retirement of life-controlled parts was also required to be reported under EASA rules, the letter argues.

“Therefore, indication from service experience nor the lack of the postulated routine inspection for bearings removed from service, can be considered as contributory factor[s] for this accident,” it adds.

Further, the letter says the AAIB failed to consider other hypotheses for the underlying causes of the bearing failure, including the possibility of manufacturing defects.