Technology & Innovation
Vertical Aerospace Advances VX4 eVTOL with Successful Wingborne Flight Testing
Vertical Aerospace completes Phase 3 wingborne tests of VX4 eVTOL, preparing for transition testing and 2028 certification.
Vertical Aerospace has reached a pivotal milestone in the development of electric vertical takeoff and landing (eVTOL) aircraft by completing Phase 3 wingborne flight testing of its VX4 prototype. This achievement positions the company for the next critical step: transition testing, which will demonstrate the VX4’s ability to seamlessly shift between vertical (helicopter-like) and horizontal (airplane-like) flight modes. Such progress places Vertical among the global leaders in eVTOL development, as it moves through a rigorous four-phase test program targeting type certification by 2028. The recent wingborne flights have yielded over 22 billion data points, validating the aircraft’s aerodynamic models, acoustic signatures, system reliability, and performance.
These technical advancements come at a time of significant momentum for the eVTOL industry, which is projected to expand from $13.9 billion in 2024 to $37 billion by 2033. This growth is being driven by rapid urbanization, heightened environmental awareness, and innovations in battery and propulsion systems. The success of the VX4’s wingborne flights marks an important validation for both Vertical Aerospace and the broader eVTOL sector, signaling that commercial electric air mobility may soon become a reality in urban and regional markets.
In this article, we examine the technical, regulatory, and market context for Vertical Aerospace’s recent achievements, analyze the VX4’s design and testing program, and explore the broader implications for the evolving eVTOL landscape.
The eVTOL sector has emerged as one of the most promising areas within aviation, propelled by advances in battery energy density, electric propulsion, and lightweight composite materials. The global eVTOL market was valued at $13.9 billion in 2024 and is forecast to reach $37 billion by 2033, reflecting an annual growth rate of 11.4%. This expansion underscores the industry’s potential to address urban mobility challenges and support sustainable transportation solutions.
Urban air mobility (UAM) is central to this vision, offering a way to bypass congested city streets and provide efficient, point-to-point air travel. Advances in battery technology have made electric flight increasingly viable for short-range, high-frequency operations typical of urban environments. At the same time, modern flight control systems and lightweight, high-strength composites have enabled new aircraft configurations that combine vertical takeoff and landing with efficient cruise flight.
Founded in Bristol in 2016, Vertical Aerospace is one of the leading European eVTOL developers. Bristol’s long-standing aerospace industry has provided access to skilled talent and established supply chains. The eVTOL sector is highly competitive, with major players such as Joby Aviation and Archer Aviation in the US, and Eve Air Mobility and Lilium in Europe. The industry has seen consolidation, with six firms attracting about 76% of total funding (approximately $5.5 billion), highlighting the capital-intensive and technically demanding nature of bringing eVTOLs to market.
The VX4 is a fixed-wing, tiltrotor eVTOL designed to carry a pilot and up to four passengers. Its four forward-tilting propellers enable both vertical takeoff/landing and efficient forward flight. The aircraft’s streamlined, composite fuselage minimizes weight while maximizing structural integrity, supporting the performance demands of urban air operations.
Key design features include high-aspect-ratio wings for improved lift-to-drag ratio, low-drag enclosed propellers to reduce noise, and integrated redundancies throughout the propulsion and fly-by-wire flight control systems. The VX4’s projected range is 100 miles (160 km) with a top speed of 150 mph (240 km/h). Recent test flights have demonstrated a top speed of 120 knots (222 km/h) and a maximum altitude of 2,000 feet. Safety is integral to the VX4’s design, with redundant systems, a ballistic recovery parachute, and robust fly-by-wire controls. Its electric powertrain offers zero-emission operation and is expected to lower maintenance costs due to fewer moving parts compared to conventional aircraft.
“The VX4’s design philosophy centers on maximizing safety, efficiency, and urban compatibility, key attributes for next-generation air mobility.”
Vertical Aerospace’s flight testing is structured in four phases: tethered hover (Phase 1), thrustborne (Phase 2), wingborne (Phase 3), and transition flight (Phase 4). Each phase systematically validates critical aspects of the VX4’s performance and safety.
Phase 1, completed in September 2024, focused on tethered hover and basic flight control validation. Phase 2 (thrustborne), completed in February 2025, demonstrated stable vertical takeoff, landing, and low-speed maneuvering. Phase 3 (wingborne), completed in September 2025, validated the VX4’s ability to fly and land like a conventional airplane, with lift generated by its wings. This phase included piloted flights covering 250 miles (400 km) and a notable 17-mile inter-airport flight between Cotswold Airport and RAF Fairford for the Royal International Air Tattoo.
Over 22 billion data points were collected during wingborne testing, providing robust evidence for aerodynamic, acoustic, and system reliability models. Regulatory approval for open airspace testing was secured in collaboration with the UK Civil Aviation Authority and EASA, reflecting confidence in the VX4’s safety and technical documentation.
“The aircraft performed exactly as modeled in our simulators, validating years of engineering work and simulation.”, Simon Davies, Chief Test Pilot, Vertical Aerospace
The imminent Phase 4 transition testing is considered the most technically complex. It will demonstrate the VX4’s ability to shift from vertical (thrustborne) to horizontal (wingborne) flight and back again, a defining capability for tiltrotor eVTOLs. This requires precise coordination between propulsion, flight controls, and aerodynamic surfaces to ensure safety and stability throughout the transition.
Transition testing builds on lessons from industry peers. Joby Aviation and Beta Technologies have both achieved piloted transitions with their full-scale prototypes, providing valuable precedents. Vertical’s systematic approach, comprehensive data collection, and regulatory engagement provide a strong foundation for this critical phase.
Successful transition testing is expected by the end of 2025, supporting the company’s goal of type certification by 2028. This milestone will demonstrate the VX4’s readiness for commercial passenger operations in urban and regional settings.
Vertical Aerospace operates in a highly competitive market dominated by a handful of well-funded players. US-based Joby Aviation and Archer Aviation have achieved significant flight testing milestones and established strategic partnerships with major airlines and Manufacturers. Eve Air Mobility, backed by Embraer, boasts a substantial order backlog and industry support. Vertical’s competitive advantages include approximately 1,500 pre-Orders from major airlines such as American Airlines, Japan Airlines, and GOL, as well as partnerships with aerospace suppliers like Honeywell, Rolls-Royce, Leonardo, and GKN. The company’s asset-light manufacturing strategy leverages Aciturri Aerostructures for airframe production, reducing capital requirements and accelerating development. The operational partnership with Bristow Group provides a “ready-to-fly” model, offering customers access to certified aircraft, pilots, and maintenance.
Despite industry consolidation, evidenced by Lilium and Volocopter’s recent insolvency proceedings, Vertical’s diversified partnerships and strong pre-order book strengthen its position as a leading contender in the global eVTOL race.
As of March 2025, Vertical Aerospace reported £66.8 million in cash and cash equivalents, with current resources projected to fund operations through Q4 2025. The company remains pre-revenue, with ongoing capital requirements typical of aircraft development programs. A recent public offering raised $90 million, including $25 million from Mudrick Capital, signaling continued investor confidence.
Vertical’s strategic Partnerships are central to its business model. Aciturri supplies the VX4 airframe, Honeywell provides flight control systems, and Bristow offers operational expertise. These collaborations allow Vertical to focus on design and certification while leveraging partners’ manufacturing and operational capabilities. The appointment of Patrick Ky, former EASA Executive Director, to the board further strengthens the company’s regulatory expertise.
Regulatory efforts are focused on concurrent certification with the UK Civil Aviation Authority and EASA, aligning with evolving international standards for eVTOLs. The regulatory framework addresses performance-based safety objectives, with graduated compliance standards based on aircraft size and intended use. Vertical’s regulatory progress is evidenced by approvals for open airspace testing and ongoing engagement with authorities.
“The collaboration between the FAA and EASA on eVTOL certification guidelines is paving the way for global market access and harmonized standards.”
Battery technology remains both the enabler and the primary constraint for eVTOL performance. eVTOL batteries face unique challenges, including high-power demands during takeoff and landing, frequent cycling, and limited opportunities for thermal recovery. Research by Oak Ridge National Laboratory has led to new electrolyte formulations tailored for eVTOL mission profiles, showing improved capacity retention during demanding flight phases.
Manufacturing innovations, such as advanced analytics, blockchain traceability, and predictive maintenance, are being integrated to improve battery quality and performance. Partnerships between battery manufacturers and eVTOL developers are emerging to address aviation-specific requirements, reflecting the need for specialized solutions beyond those used in automotive or consumer electronics.
While some industry leaders are optimistic about future battery improvements, others remain cautious. Airbus Helicopters, for example, has paused its eVTOL program pending further advances in battery maturity, citing current limitations in range, performance, and cost-effectiveness. The eVTOL market spans passenger transport, cargo delivery, emergency services, and government applications. Urban air mobility is the primary focus, with the VX4’s range and speed well-suited for city-center to airport transfers and regional commuting. Major airlines have placed significant pre-orders, reflecting confidence in the technology’s commercial potential.
Beyond passenger operations, eVTOLs offer potential for rapid cargo delivery and medical transport, with lower operating costs and noise profiles than helicopters. Infrastructure development, including vertiports and charging stations, will be critical for supporting widespread adoption.
Vertical’s “ready-to-fly” operational model, developed with Bristow, lowers barriers for operators by providing turnkey access to certified aircraft and operational support. This approach could accelerate adoption and market penetration, especially in regions with limited aviation infrastructure.
Vertical Aerospace’s recent achievements mark a major step toward commercial eVTOL operations. The company’s methodical testing program, robust data collection, and regulatory collaboration provide a strong foundation for type certification and commercial deployment. The transition testing phase, expected to conclude by the end of 2025, will be a defining milestone for the VX4 and the broader industry.
The eVTOL sector is poised for significant growth in the late 2020s, contingent on continued technical progress, regulatory harmonization, and public acceptance. Advances in battery technology, infrastructure development, and operational partnerships will be key enablers. As eVTOLs move closer to commercial reality, their integration into urban transportation systems could reshape urban planning and accelerate the adoption of sustainable aviation.
What is the VX4 and what makes it unique? What are the key milestones achieved by Vertical Aerospace recently? When is commercial certification expected for the VX4? Who are Vertical Aerospace’s major partners and customers? What are the main challenges facing the eVTOL industry? Sources:Vertical Aerospace Advances Toward Commercial eVTOL Aviation with Successful Wingborne Flight Testing and Imminent Transition Phase
Background and Industry Context
VX4 Aircraft Design and Specifications
Flight Testing Program and Recent Achievements
Transition Testing Phase and Technical Challenges
Market Position and Competitive Landscape
Financial Performance, Partnerships, and Regulatory Progress
Technology Trends and Battery Developments
Market Opportunities and Commercial Applications
Future Outlook and Industry Implications
FAQ
The VX4 is a fixed-wing, tiltrotor eVTOL developed by Vertical Aerospace. It combines vertical takeoff and landing capability with efficient forward flight, using four tilting propellers and lightweight composite construction for urban and regional air mobility.
Vertical has completed Phase 3 wingborne flight testing, validating aerodynamic and system performance, and is preparing for transition testing, which will demonstrate seamless shifts between vertical and horizontal flight modes.
Vertical Aerospace targets type certification for the VX4 by 2028, aligning with timelines from other leading eVTOL developers.
Key partners include Aciturri Aerostructures (airframe manufacturing), Honeywell (flight controls), and Bristow Group (operations). Major customers with pre-orders include American Airlines, Japan Airlines, and GOL.
The industry faces technical challenges in battery performance, certification complexity, capital requirements, and the need for supporting infrastructure and public acceptance.
Vertical Aerospace
Photo Credit: Vertical Aerospace