Manufacturer Unveils its New Piper Seminole DX in DeltaHawk Partnership

Iconic general aviation manufacturer Piper Aircraft has unveiled a new addition to its trainer class: the Piper Seminole DX. The diesel-powered machine uses a pair of FAA-certified, 180-horsepower DeltaHawk engines to save on fuel and maintenance costs while boosting performance.

Designed to run on JET A and JET A-1 (with SAF approval in progress), the DHK4A180 engines offer about 40% better fuel efficiency than typical avgas piston engines. The system includes full-feathering three-blade props and counter-rotating engines, with a Piper-owned STC used for factory integration. The aircraft also features a more capable cabin heat and cooling system, allowed by the liquid-cooled engine design.

According to Piper, the switch to heavy fuel offers significant savings in fuel and maintenance costs while providing noticeable improvements in single-engine performance. The Seminole DX reportedly burns 35% less fuel than the standard model, climbs 32% faster on one engine, and offers a 70% higher single-engine ceiling.

“The market has been heard loud and clear regarding the need for a reliable, cost-effective, heavy fuel, multi-engine training platform,” said John Calcagno, President and CEO of Piper Aircraft. “The new Seminole DX fills that market void perfectly.”

The project claims to have already drawn widespread international attention, with Piper projecting demand for 25 to 40 aircraft annually over the next decade. Flight testing is set to begin in November 2025, with FAA certification expected by Q3 2026. Piper also plans to pursue certification in Canada, Europe, and India, and begin deliveries in late 2026 or early 2027.

“The installation of our certified DHK engine in the legendary Piper Seminole is a perfect match with our industry-unique features to provide the lowest cost of ownership and the simplest and safest multi-engine training platform ever,” added DeltaHawk Engines CEO Christopher Ruud.

The Seminole DX is not Piper’s first diesel rodeo. The manufacturer debuted a diesel version of its ever-popular Archer trainer in 2014 and has recently confirmed several large orders, including a 2025 contract with Air India for up to 93 Archer DX.

FMI: www.piper.com