The University of North Dakota’s John D. Odegard School of Aerospace Sciences (UND Aerospace) has placed an order for up to 188 Piper airplanes worth about $155 million, the manufacturer’s largest-ever order, according to Piper president and CEO John Calcagno. The company also announced that it is developing the Seminole DX, a version of the twin-engine trainer that will be powered by DeltaHawk’s 180-horsepower DHK4A180 compression ignition (diesel) engine.
UND Aerospace’s order, announced at the EAA AirVenture show on July 22, starts with an initial 145 airplanes that include the Archer TX and Seminole, with deliveries beginning in 2027 and lasting eight years. An optional two-year extension through 2036 could bring the total to 155. The university’s last large order with Piper was for 112 airplanes, which concludes in 2026.
“Piper remains a vital collaborator in the continued success of flight training at UND,” said Robert Kraus, dean of UND John D. Odegard School of Aerospace Sciences. “We look forward to strengthening our relationship as we prepare the next generation of pilots for careers in the airlines, business aviation, and the U.S. military. The entire Piper team has been outstanding—responsive to our needs and collaborative in enhancing the components and capabilities of the Archer TX and Seminole.”
During the EAA AirVenture event in Oshkosh, Wisconsin, Piper opened the order book for the Seminole DX and displayed a Seminole wing equipped with a DeltaHawk engine at the Piper exhibit. Calcagno said the company will release pricing for the Seminole DX later this year.
Seminole Upgrade Announced
Compared to the avgas-burning Seminole, the DX has a 35% lower fuel burn (15.1 gph at 75% power at 6,000 feet versus 23.3 gph in the avgas Seminole), 32% increase in single-engine climb rate at 2,000 feet (161 fpm versus 122 fpm), and a 70% higher single-engine service ceiling (8,500 feet from 5,000 feet).
The DeltaHawk engine is liquid-cooled and runs on jet-A fuel. Piper is developing the supplemental type certificate for installation of the DeltaHawk engine in the Seminole, and the firewall-forward kit will include all the necessary equipment and three-blade, full-feathering, counter-rotating propellers. The airplane will also be equipped with a cabin temperature control system that uses the liquid cooling system to provide heat.
Flight testing for certification is planned in November, with FAA approval expected in the third quarter of 2026 and deliveries beginning in 2027. Piper plans to add certification from Transport Canada and India’s DGCA.
“The market has been heard, loud and clear, regarding the need for a reliable, cost-effective, heavy fuel, multi-engine training platform,” said Calcagno. “The new Seminole DX fills that market void perfectly. Based on interest received since our MOU announcement last year, we anticipate global market demand for the Seminole DX to be between 25 to 40 aircraft per year over the next 10 years.”
Piper also announced a purchase agreement from United Aviate Academy for up to three Seminoles plus options, with deliveries scheduled for later this year. This marks the academy’s new membership in the Piper Flight School Alliance. Paragon Flight Training is extending its all-Piper fleet with delivery of six more Pilot 100i trainers by the end of the year and more orders into 2027. Sierra Charlie Aviation is taking delivering of a Seminole this year.