Vertical’s VX4 eVTOL Program Moves to Next Phase

Vertical Aerospace shares an update on its VX4 eVTOL program including flight tests, incident, certification progress, and assembly of a second prototype By Joe Macey / 01 Sep 2023
Vertical's VX4 Program Moves to Next Phase
Follow AAMi

Vertical Aerospace has provided an update on its overall program including the flight test campaign and a VX4 eVTOL prototype crash.

Flight Test Update

Vertical concluded its remote thrustborne flight test campaign in July 2023, as the first full-scale VX4 prototype reached its target speed of 40kts (70 kmph), demonstrating exceptional overall stability and control. Performance targets were generally exceeded by 10-30% during hover and low speed flights. The prototype performed especially well in sustained hover, typically the most challenging regime for a VTOL aircraft, where it maintained level flight for longer than anticipated. The aim of these thrustborne flight tests was to verify acceptable stability, battery efficiency and control characteristics, aerodynamics, structural loads, performance and vibration throughout this speed range – all of which were achieved.

Incident Update

Vertical continued further uncrewed flight tests following the completion of the remote thrustborne flight test campaign. The purpose of these was to understand how the aircraft performed outside of its expected operating conditions before the aircraft’s planned retirement.

During one of these test flights, an unexpected fault occurred causing the aircraft to enter a stable descent, before being damaged on impact with the ground. Vertical completed a swift and thorough investigation and submitted a report to the Air Accidents Investigation Branch (AAIB). Vertical’s investigation identified the root cause to be a fault with a propeller. This early generation propeller had already been redesigned prior to the incident, with the issue fully resolved ahead of the next phase of testing. Further recommendations by the investigation are being implemented by Vertical.

Vertical believes transparency and openness is fundamental to the safety of aerospace. It therefore intends to provide a further full update to the industry on the incident once the AAIB’s investigation has concluded.

VX4 Program Update

Supported by the learnings from the completed thrustborne campaign, the VX4 and its certification program remains on track with no changes to timelines. The assembly of a second significantly more advanced full-scale VX4 prototype is underway at GKN Aerospace’s Global Technology Centre. This demonstrator is expected to be ready to fly early next year. Its components will include technology from most of Vertical’s certification partners: Honeywell, GKN Aerospace, Hanwha, Solvay, Leonardo and Molicel. An additional, identical full-scale aircraft has also now been approved and is expected to be flying in the second half of 2024.

These upgraded full-scale aircrafts’ structures and subsystems will be tested in line with certification standards. Both will require rigorous regulatory oversight, including a Permit to Fly from the UK Civil Aviation Authority, to progress to piloted flying.

Stephen Fitzpatrick, Vertical Founder and CEO commented: “We are pleased with our flight test progress to date and the data, insights and invaluable learnings we have collected. While a fault of any sort is disappointing, it is not wholly unexpected at this stage of testing a novel aircraft. I am pleased that as a result of our expert team we have isolated the cause of the fault and been able to provide the AAIB with our report within 14 days of the incident. Our planned second upgraded prototype, which will include most of our top tier partners’ technology, will have us in the air early next year and we remain on track for our certification timelines.”

Posted by Joe Macey Joseph Macey is a Content Specialist at Advanced Air Mobility International, focusing on emerging aviation technologies since joining in 2022. He has particular expertise in eVTOLs, vertiports, and propulsion systems. A graduate of Falmouth University in Journalism, Joseph began his career in 2019 as a local reporter. His journalism experience sharpens both his reporting and interview skills, enabling him to deliver well-informed, authoritative insights on the latest trends in the aviation sector. Connect

Latest Articles

Skyportz Unveils Aeroberm Vertipad at Dubai Airshow

New modular landing system from Skyports aims to enable property developers and asset owners to join the Advanced Air Mobility network affordably and safely

Nov 21, 2025
Hybrid-Electric VTOL Aircraft Program Secures Major Investment & Partnership

Ambitious Air Mobility Group is partnering with Zuri.com to accelerate the certification and production of hybrid-electric vertical take-off and landing platforms

Nov 20, 2025
EHang Completes Pilotless eVTOL Flights in Doha

EHang's trial operation demonstrated the potential for Urban Air Mobility and aerial shuttle service in the Middle East, connecting key city landmarks

Nov 19, 2025
Vertical’s VX4 eVTOL Prototype Enters Piloted Transition Testing Stage

Vertical Aerospace begins Phase 4 transition testing of its VX4 prototype after receiving a Permit to Fly from the UK Civil Aviation Authority, marking the start of piloted transition evaluations

Nov 18, 2025
TCab Tech Launches Global ‘Air Silk Road’ Initiative & NexAvian Partnership to Drive eVTOL Expansion

The program, launched at the China International Import Expo, is designed to build a global ecosystem for Advanced Air Mobility and accelerate the international rollout of the E20 eVTOL

Nov 17, 2025
Archer Completes In-Country Flight Tests in UAE for Midnight eVTOL Aircraft

In-country flight campaign in the UAE showcases the Archer aircraft’s full flight envelope over desert areas, supporting the goal of making Abu Dhabi the first region for commercial operations

Nov 14, 2025