Diesel-powered plane potentially a New Zealand first


A 20-year quest to refurbish a diesel engine in a top dressing airplane is gaining altitude for Bill Sutherland.

Phoenix Aviation Maintenance aeronautical engineer Peter Kempthorne, his team and Mr. Sutherland work on the project at Gore Airfield.

Mr. Sutherland is the former owner of Sutherland’s Tranport in Waikaka.

Having worked with diesel-powered trucks all his life, he enjoyed diesel engines, Mr Sutherland said.

“I always thought why you couldn’t put a diesel engine in a top dressing airplane.”

He purchased a 1982 Fletcher FU 24 top dressing aircraft in 2012 with the intention of replacing its turbine engine with a diesel engine.

He started researching how to do this and eventually, after a few false starts, found a company in Germany that made diesel aircraft engines.

He and Mr Kempthorne consulted with Flight Structures Design Certification Engineer Murray MacGregor of Hamilton who did the calculations to make sure what they had planned would work.

They employed Mr MacGregor so the plane would meet the requirements of the Civil Aviation Authority of New Zealand, Mr Kempthorne said.

“We have to do it to a standard so it can be duplicated.

“It’s not unique.

“You call it a modification.”

The pair thought the plan was that good others in the industry would benefit.

“It’s an improvement and we believe it should be replicable as a continuous improvement,” Kempthorne said.

The 500 horsepower V12 diesel engine ran on both diesel and Jetfuel A1 which was similar to kerosene, Mr Sutherland said.

“It would run very well on diesel, which is a much cheaper option than Avgas (aviation fuel)…but there’s no quality control on diesel, so civil aviation won’t allow it. .”

The Fletcher’s old 400 hp engine used 110 liters of Avgas per hour when running, but the new engine would use 80 liters of jet fuel per hour.

“The engine is inherently more economical.”

If the plane carried less fuel, it was lighter and could carry more fertilizer.

Not only was the new engine more fuel efficient, but the Jetfuel was cheaper than the Avgas.

Any savings that could be made on fuel are welcome given that fuel costs are rising and fertilizers still need to be spread on farms, they said.

The aircraft could also be used for skydiving.

Test pilot Bill O’Connor had already flown on two flights and the results looked promising, they said.

While there were foreign companies making planes with diesel engines, there were none in New Zealand, they said.

Mr Sutherland was now awaiting certification from the Civil Aviation Authority so the plane could be put to work, he said.

-Sandy Eggleston

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