Vertical Aerospace has seen its latest VX4 prototype perform its first tethered piloted flight as it begins the ‘wheels up’ phase of testing. This VX4 performed a piloted flight while loosely tethered to the ground, during which Vertical measured over 20,000 flight and system parameters to verify thrust, handling qualities and system performance.

The tethered piloted flight took place after the UK CAA had issued a Permit to Fly for the VX4 prototype, having rigorously evaluated the engineering, design, test data and aircraft, effectively conducting a ‘mini certification’ programme of the aircraft.

Vertical must submit documentation to the CAA to move through each flight phase, including extensive, detailed documentation covering every aspect from safety protocols and engineering specifications to operational procedures.

Following initial tethered flights, and once it has received permission from the CAA to expand the flight envelope, the VX4 will enter the next phase of testing which will start with further thrustborne flight testing. This will see the VX4 take off and land vertically and conduct low speed flight manoeuvres with lift generated by the propellers. Wingborne or conventional flight (CTOL) and the final critical test stage of piloted transition flight will follow once the CAA's rigorous approval for this final phase of testing has been granted.

In advance of this first tethered flight, the VX4 successfully completed extensive ground testing, including powered propulsion testing of its advanced powertrain, which features proprietary battery packs capable of delivering 1.4MW of peak power and which has been designed and built at the Vertical Energy Centre.

CEO Stuart Simpson says: “The first tethered flight of our new VX4 prototype is the result of 14 months of hard work, taking this advanced aircraft all the way from design, through to development and now into the air. This moment is testament to the skill and commitment of hundreds of talented colleagues in our business who have made our VX4 aircraft the best eVTOL out there. Everyone at Vertical Aerospace remains laser focused on achieving piloted transition as we continue to progress towards our ultimate goal of commercialisation and creating a new legacy for aviation.”