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Tales of Robo cracking cylinders and class actions - 

Via Ironsider in the Oz...

Class action looms in chopper probe

ROBYN IRONSIDE

A mystery gremlin causing potentially dangerous cracking in helicopter engine cylinders could be the subject of a major class action once the culprit is found.

An investigation by the Australian Helicopter Industry Association with assistance from the Australian Transport Safety Bureau aims to pinpoint the cause before mustering season gets into full gear in April.

AHIA and investigation chairman Ray Cronin said the premature cracking of exhaust valves in piston engines had increased by up to 400 per cent over the past four years.

“There’s really two issues — an inlet valve issue and an exhaust valve issue,” Mr Cronin said.

“The inlet valve failures are a lot more dramatic — they have a sudden loss of power. The exhaust valve failures are less aggressive yet the power denigration is significant.

“In that situation where a pilot needs the full power available, that could easily lead to an accident and we need to prevent this.”

The helicopters most vulnerable to the problem are the Robinson R22s and the R44 Raven 1s, with an estimated 700 cylinders being replaced in the Northern Territory in the past four years.

Mr Cronin said the investigation was leaving “no stone unturned”, looking at every possible cause including climate, parts supply and fuel.

Although no crashes had been linked to the issue, Mr Cronin said aircraft had been landing prematurely.

North Australian Helicopters’ head of maintenance Steve Minear said the problems had coincided with a reduction in the lead content in the fuel supply.

“We had a presentation from Viva Energy and they’re claiming it’s not the fuel,” Mr Minear said.

“But pretty much the only thing that’s changed in the last few years is the fuel, and in the last 12 months we’ve had to replace 50 or 60 cylinders. It’s an expense to the industry.”

He said as a result of the premature cracking, North Australian Helicopters had adjusted its maintenance schedule to check the valves every 100 hours, instead of every 300 hours.

“If it is the fuel that’s caused these issues, I could see possibly a class action,” said Mr Minear.

A Viva Energy spokesman said the company was an active part of the investigation group.

“Viva Energy is a long-term manufacturer of avgas in Australia and our fuel, supplied throughout most of the country, meets all relevant fuel quality specifications with no quality or operability issues,” he said.

Lycoming, which is the primary affected engine manufacturer, is also part of the investigation group.

Mr Cronin said the investigation was continuing at an accelerated pace, and they hoped to have answers in weeks rather than months.

“We’re calling for any operator who’s had any problems associated with this to get in touch with us,” he said.

MTF...P2