The image of the Jet-A four-cylinder DeltaHawk engine below is from coverage I did at AirVenture in 2019, when the Wisconsin-based company was expecting FAA certification by the end of that year. Nearly four years later, DeltaHawk announced that the FAA has finally issued type certification for the DHK180A4—the first of a family of engines with varying power.
Yes, it took many years and a lot of money for the FAA TC, and while naysayers may have once written off DeltaHawk as a serious contender (at least in the GA engine market—there are plenty of other potential applications for this engine), it’s tough to argue that the certified and experimental markets are growing desperate for more engine choices.