Joby Aviation and L3Harris Team Up to Pioneer Hybrid VTOL for Defense

Joby Aviation, a leader in electric vertical take-off and landing (eVTOL) aircraft, has partnered with defense contractor L3Harris Technologies to develop a groundbreaking gas-turbine hybrid VTOL aircraft designed for military applications. Announced on August 1, 2025, by TechCrunch, this collaboration leverages Joby’s advanced air taxi technology and L3Harris’ expertise in military systems to create a versatile, optionally piloted aircraft for low-altitude defense missions. With flight testing set to begin this fall and operational demonstrations planned for 2026, this initiative could redefine military aviation. Here’s a deep dive into the partnership, its potential impact, and the challenges ahead.

The new aircraft builds on Joby’s S4 platform, originally developed for commercial air taxi services. Unlike its all-electric prototype, this version uses a gas-turbine hybrid powertrain, offering extended range and flexibility for defense needs. Joby demonstrated the technology’s potential in June 2024, flying a hydrogen-electric hybrid 561 miles—over twice the distance of its battery-powered model. The partnership with L3Harris, a top-tier defense contractor, integrates sensors, communication systems, and collaborative autonomy, enabling the aircraft to operate either autonomously or with a pilot. This dual capability, as noted by L3Harris’ Jon Rambeau, supports “long-range, crewed-uncrewed teaming” for missions like reconnaissance or logistics.

Joby’s decade-long relationship with the U.S. Department of Defense (DoD) has shaped this project. Through the Air Force’s Agility Prime program, Joby refined its eVTOL technology, securing a $131 million contract to deliver and operate aircraft for military testing. The focus on hybrid propulsion addresses the DoD’s demand for longer-range platforms, as battery-powered eVTOLs often lack sufficient payload and endurance for defense applications. Joby’s acquisition of Xwing’s autonomy division in June 2024 further bolsters its ability to deliver fully autonomous flight, a key requirement for modern military operations.

The collaboration is a strategic win for both companies. Joby, still pursuing FAA Type 1 certification for its commercial air taxis, gains a faster path to revenue through defense contracts, bypassing the lengthy civilian certification process. Its California manufacturing hub, recently expanded to double production capacity, supports this dual-purpose strategy. L3Harris brings its expertise in missionizing aircraft—equipping them with sensors and communication systems—enhancing the S4’s utility for defense. The partnership aligns with a broader industry trend, as competitors like Archer Aviation and Beta Technologies also develop hybrid eVTOLs for military use, signaling a shift away from purely electric platforms.

Market response has been strong. Joby’s stock has surged over 100% in 2025, reflecting investor confidence in its defense and commercial prospects. L3Harris, with a 30% stock increase, benefits from its role as a “nimble prime” contractor, per Joby’s Paul Sciarra. The deal could lead to significant DoD contracts if flight tests this fall and demonstrations in 2026 prove successful. However, risks remain, including the technical challenge of integrating hybrid propulsion with autonomous systems and meeting stringent military standards.

Challenges include regulatory and operational hurdles. While Joby has completed three of five FAA certification stages for its commercial eVTOL, adapting the S4 for defense requires navigating separate military airworthiness criteria. L3Harris must ensure its missionization—adding sensors and payloads—meets DoD expectations without compromising performance. The partnership also faces competition from established defense contractors and other eVTOL startups, all vying for a share of the growing military drone market. Additionally, scaling production while maintaining quality and managing costs could strain Joby’s resources, especially as it balances commercial and defense goals.

For the DoD, the hybrid VTOL offers a cost-effective alternative to traditional helicopters, which can cost $30 million each. Its smaller size, autonomy, and adaptable payloads suit diverse missions, from surveillance to troop transport. For the public, Joby’s dual-purpose technology could accelerate commercial air taxi deployment, as defense contracts fund innovations that trickle down to civilian services. However, the environmental impact of gas-turbine hybrids, compared to all-electric models, raises concerns among sustainability advocates, given Joby’s original green mission.

This partnership positions Joby and L3Harris at the forefront of next-generation aviation, blending cutting-edge technology with military precision. As they prepare for fall testing, the success of this hybrid VTOL could reshape defense strategies and urban mobility alike, provided they navigate the technical and competitive challenges ahead.