What Happened
Diesel Twin Makes AirVenture Debut With Promising Fuel Efficiency
Piper Aircraft is showcasing the first flying prototype of its DeltaHawk-powered Seminole DX at EAA AirVenture Oshkosh 2026, following its maiden flight on July 2. The aircraft is powered by two FAA-certified DeltaHawk DHK4A180 engines and has demonstrated promising fuel efficiency, with preliminary data showing a climb rate of about 1,700 feet per minute and fuel consumption roughly 35% lower than the standard avgas-powered Seminole. According to Piper President and CEO John Calcagno, the company has seen strong interest in the Seminole DX, particularly from flight schools in Europe and the Asia-Pacific region. This development was first reported by AeroTime.