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Diamond pursues engine alternativesDiamond pursues engine alternatives

Diamond Aircraft is seeking Canadian and FAA approval to put Lycoming IO-360 engines on the DA42 Twin Star in place of diesel engines.

Thielert Aircraft Engines, the German company that built the original diesel engine, remains in bankruptcy. Given emerging new technical problems with the engine, Diamond officials said they are concerned Thielert will not survive.

In the meantime, Diamond and Austro Engine are seeking approval to make parts and provide support for the Thielert engine.

Diamond continues to pursue certification of a separate diesel engine made by Austro Engine, but certification could take most of this year for approval in Europe, and not before 2009 in the United States.

Although Thielert is bankrupt, Frank Thielert continues as general manager under the watchful eye of the bankruptcy administrator. Diamond Aircraft has registered along with dozens of other companies to become an investor in Thielert as part of the bankruptcy proceedings. Talks on that subject will occur in a few weeks, bankruptcy administrators say.

Diamond officials said in mid-June that they have concerns over the failure of Thielert to resume engine production. The next day, the bankruptcy administrator issued a press release stating production had started. A spokesman said production resumed only days earlier, and he could not predict when a finished engine would emerge from the plant in Germany.

Bankruptcy administrators have been accused by Diamond officials of overcharging for spare parts.

Flying the Lycoming-
powered Twin Star

By Thomas A. Horne

Talk of Diamond switching its DA42 Twin Stars to 180-hp Lycoming IO-360 engines caused a stir this week.

But the fact is that such an airplane has been in the works since 2004. I know because I flew a proof-of-concept Lycoming-powered Twin Star back in the fall of that year. All I can say is that the airplane’s extra power (360 total horsepower versus the 270 horses of the 1.7-liter Centurion TAEs) made the Lycoming Twin Star a hot rod by comparison.

The airplane leapt off the runway and climbed at 2,000 fpm doing 125 KIAS. As for cruise flight, I had to pull the Lycomings back to 20 inches of manifold pressure and 2,100 rpm to keep from busting the airframe’s V NE of 161 KIAS. (This prototype was limited to the DA40’s redline in the interest of safety.) That would have been 55- to 60-percent power in any other IO-360 installation—but in the Lycoming Twin Star prototype this power setting produced 161 KIAS.

So if it’s performance you want, a Lycoming-powered Twin Star could certainly fill the bill. It’s something that would make real sense in the American market with better parts and service for Lycoming engines.

Alton Marsh

Alton K. Marsh

Freelance journalist
Alton K. Marsh is a former senior editor of AOPA Pilot and is now a freelance journalist specializing in aviation topics.

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