Sept 12 (Reuters) - UK-based Vertical Aerospace ( EVTL )

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.

The company is now preparing for phase two testing, which

will involve taking-off and landing vertically and conducting

low-speed flight maneuvers with lift generated by the

propellers.

Founded in 2016, Vertical is developing a piloted,

four-passenger electric vertical take-off and landing (eVTOL)

aircraft.

The company's founder, Stephen Fitzpatrick, missed a

previously agreed deadline to inject a portion of cash he had

promised into the eVTOL maker, Bloomberg reported earlier this

month.

Without additional funding, Vertical risks running out of

cash by March 2025, the report added.

"Vertical remains in ongoing discussions with Stephen.

Stephen remains fully supportive of the Company," Vertical said

in a statement to Reuters.

In the first half of the year, Vertical brought in funds,

including additional cash from Rolls-Royce, taking its unaudited

cash reserves to $84 million as of June 30, the company added.