Vertical Aerospace has started ground testing the fully integrated hybrid-electric powertrain for its Valo aircraft at the company’s Flight Test Centre at Cotswold Airport in the UK.
The work is being conducted on Vertical’s Hybrid Propulsion Evaluation Rig (HYPER), which enables full system integration and validation of the hybrid powertrain, including the turbine, generator and associated electrical systems.
The rig is also being used to test control architecture, system response and fault scenarios ahead of aircraft-level ground and flight testing. The work follows more than two years of development at the Vertical Energy Centre in Bristol, UK.
Vertical is working with several partners to integrate a sustainable aviation fuel (SAF)-compatible gas turbine with an electric generator, while leading development of system integration, control architecture and software.
The resulting turbogenerator will be integrated into a prototype hybrid-electric version of the Valo aircraft for flight testing and demonstrations, and will also support development and validation of technologies for future hybrid variants.
Vertical is targeting certification of the hybrid-electric variant with the UK Civil Aviation Authority (CAA) and the European Union Aviation Safety Agency (EASA).
The four-passenger Valo electric vertical take-off and landing (eVTOL) aircraft is currently undergoing certification with the same authorities, having completed a piloted two-way transition flight in April. The hybrid-electric variant is expected to deliver a targeted range of up to 1,000 miles — a ten-fold increase on the all-electric aircraft — and a payload of up to 2,425 lb (1,100kg).
Beyond extended range and payload, the hybrid-electric variant is targeted to provide low noise and heat signatures suited to sensitive missions, and to be capable of crewed, remotely piloted or autonomous operation. Vertical said the uncrewed capability will be integrated into the existing Valo flight control system, which is being developed by Honeywell.
Vertical has also produced the first all-electric Valo battery from its upgraded assembly line at the Vertical Energy Centre, which was brought online in March. The 15,000ft² (1,394m²) facility, which has produced battery systems used in piloted flight testing since 2024, has been upgraded with automated, aerospace-grade processes intended to support certification and series production.
The company says it has 1,500 pre-orders for the Valo, with customers including American Airlines, Avolon, Bristow, GOL and Japan Airlines. Industrial partners on the program include Honeywell, Syensqo and Aciturri.
Stuart Simpson, CEO of Vertical Aerospace, said, “Hybrid capability complements our all-electric Valo platform and unlocks a broader range of civil and defence applications. At the same time, advancing our battery technology and manufacturing capability is critical to certification and scaling production.”
