Vertical was busy this summer conducting a thorough remote thrustborne flight test campaign. It tested things like battery efficiency, structural loads, and performance throughout the speed range. The results were encouraging.
According to the builder, the VX4 prototype managed to reach the target speed of 40 knots (70 kph) and perform well during sustained hover, which is usually the most sensitive testing area for eVTOLs. It even claims to have exceeded performance targets by up to 30% during low-speed flights and hover.
In early August, the prototype suffered a significant incident. During another uncrewed flight test, the aircraft fell from the sky and hit the ground, resulting in damage. The builder launched its own investigation and also reported the incident to the AAIB (Air Accidents Investigation Branch). In short, a faulty propeller was the issue. However, the good news is that the propeller had already been redesigned prior to the incident.
In other words, Vertical confirmed that no future VX4 aircraft would include this first-generation propeller. It also added that its core technology developed in-house, including the battery system, maintained the expected performance during the incident.
Even with this minor setback, the UK manufacturer believes it can still meet the original deadline. A second-generation, full-scale prototype of the VX4 aircraft is currently in production at the GKN Aerospace's Global Technology Center. Vertical says it's a highly advanced demonstrator that will incorporate all the technologies from Vertical's top partners.
This particular prototype is set to take to the sky early next year. A second aircraft, sporting the exact technologies, will follow shortly, during the second half of 2024. As for the first-generation prototype, it won't be retired. The Vertical team will continue to use it, but only for ground-based tests, because it's no longer airworthy, and it won't be repaired to bring it back to those standards, either.
The VX4 was introduced as a five-seat air taxi with a proprietary battery system and a 1 MW powertrain, promising a 100-mile (161 km) range at 200 mph (325 kph).