# US Army flies hybrid drone with air-cooled heavy-fuel engine

_Published Wednesday, November 4, 2026 at 6:19 AM EST · Robotics, Science · Latest · Tier 2 — Notable_

![US Army soldiers with a drone — Primary](https://cdn.mos.cms.futurecdn.net/B2RrcZbxvwMmZr7vaWb2eR-2035-80.png)

US Army Research Laboratory researchers have flown the VICTOR hybrid electric drone using a heavy-fuel rotary engine developed with metal 3D printing, Tom's Hardware reported. The design replaces a bulky liquid cooling system with air cooling, reducing the propulsion system's size.

The engine runs a 400-volt motor-generator that supplies electricity to the propeller motors rather than driving the propellers mechanically. That arrangement lets the engine operate independently at its optimal speed. Researchers also improved fuel atomization and reduced compression leaks through repeated component redesigns.

VICTOR can take off and land vertically without a runway. The military has disclosed little about its battery configuration.

## Sources

- [Tom's Hardware](https://www.tomshardware.com/tech-industry/drones/us-army-successfully-flies-a-hybrid-electric-drone-with-3d-printed-heavy-fuel-rotary-engine-400v-motor-generator-uses-advanced-engineering-to-ditch-a-bulky-liquid-cooling-system)

---
Canonical: https://techandbusiness.org/newswire/O50owlJQofDyJI1jcPFIje
Published: 2026-11-04T11:19:00.101Z
Story chronology: 2026-11-04T10:30:00.000Z
Retrieved: 2026-11-04T14:11:25.275Z
Publisher: Tech & Business (techandbusiness.org)