Thielert has made inroads with diesels because Diamond signed on early.

It’s no mystery why Continental and Lycoming dominate the light aircraft engine market. They’ve been at the engine business forever, certification rules pose a strong economic barrier for new entrants and, in the end, the industry is more conservative than it’s willing to admit. Even powerplant initiatives from within the two dominant companies have rarely met with ringing success.

Although some companies keep trying, the odds are still long that a new aircraft engine will succeed in the North American market, although it might do well enough in the world market. That’s why even U.S. airframe manufacturers can’t ignore new engine ideas, even if they aren’t enthusiastic about U.S. introductions. Here’s…