UK-based Vertical Aerospace said on Thursday it had completed the first phase of piloted testing of a prototype of its flagship air taxi, VX4.

The VX4 has 1,500 pre-orders worth $6 billion from companies including Virgin Atlantic, American Airlines and Japan Airlines.

The phase one testing included multiple piloted tethered flights and ground runs, completing a total of 70 individual test points that is needed to validate the prototype's safety in real-world flight scenarios.