Swarm Aero Selects Honeywell TPE331 to Power Group 5 UAS

On June 9, 2026, California-based startup Swarm Aero announced the selection of Honeywell Aerospace’s legacy TPE331 turboprop engine to power its forthcoming Group 5 Uncrewed Aerial System (UAS). The integration of a commercially proven powerplant aims to bypass the payload and range limitations of current battery technology for large-scale autonomous defense platforms.

In a press release issued Tuesday, Swarm Aero confirmed that Honeywell has already supplied the initial propulsion systems under the contract. The partnership pairs a next-generation autonomous swarm platform with an engine originally certified in 1965, a strategy designed to reduce technical risk and accelerate production timelines for military applications.

Bridging legacy propulsion and autonomous systems

The Honeywell TPE331 brings extensive operational history to the new UAS program. Since its initial certification, Honeywell has delivered 13,000 TPE331 engines, accumulating 122 million flight hours across the commercial, agricultural, and military aviation sectors.

Swarm Aero Chief Executive Officer and Co-Founder Peter Kalogiannis noted the deep relationship required between aircraft and engine manufacturers, stating the company sought a partner that viewed them as more than just a customer.

“The TPE331 is a proven, cost-effective, high-performance engine with an extraordinary legacy, and we’re proud to build our aircraft around it,” Kalogiannis said.

Matt Milas, President of Defense and Space at Honeywell Aerospace, emphasized that the defense landscape is shifting toward distributed and autonomous operations where production scale is critical. He noted that pairing proven systems with new platforms allows the industry to field capabilities faster and more affordably.

Scaling production for Group 5 UAS operations

According to defense publication BriefGlance, the U.S. Department of Defense (DoD) defines Group 5 UAS as the largest category of military unmanned systems, encompassing aircraft weighing more than 1,320 pounds (600 kilograms) and typically operating above 18,000 feet. Platforms in this category require significant payload capacity and endurance, operational requirements that current battery technologies cannot support at scale.

To support the anticipated production volume, Swarm Aero recently opened an 80,000-square-foot Advanced Manufacturing Center in Fayetteville, Arkansas. The company, headquartered in Oxnard, California, also recently closed a $35 million Series A funding round led by Two Sigma Ventures and Silent Ventures. This brings Swarm Aero’s total raised capital to $59 million since its founding in 2022.

Oliver Palmer, Chief Revenue Officer and Co-Founder of Swarm Aero, stated the company is focused on building an ecosystem capable of producing and operating aircraft at scale, shifting the focus from individual aircraft to the capabilities of the swarm.

AirPro News analysis

We view Swarm Aero’s selection of the TPE331 as a pragmatic approach to defense procurement. By utilizing a commercial off-the-shelf powerplant with a mature global supply chain, the company avoids the lengthy and expensive development cycles associated with clean-sheet engine designs. This strategy aligns with current DoD initiatives aimed at fielding autonomous mass rapidly. The reliance on a turboprop rather than electric propulsion acknowledges the current physical limits of battery energy density for heavy, long-endurance Group 5 platforms.

Sources: Swarm Aero