ZeroAvia has made a major step forward for green energy aircraft travel. Touted as a “world first,” on Thursday the company’s Piper M-class six-seater plane completed its maiden voyage powered by a hydrogen fuel cell.

The craft had been retrofitted to run off the cell, which utilizes hydrogen and oxygen to generate electricity. The voyage consisted of a taxi, takeoff, “full pattern circuit” – a flight path in which the craft is always in view of the airfield – and, a successful landing, CNBC reported. The flight took place at Cranfield Airport, roughly 50 miles north of London.

The Piper M-class was preceded by the successful 2016 flight of the HY4 craft in Stuttgart, Germany. ZeroAvia CEO Val Miftakhov differentiated its recent flight from the earlier one by explaining that the M-class is a commercial-grade craft, while the HY4 was merely a research craft capable of carrying four passengers.

ZeroAvia’s next goal is to carry out a 250-300 nautical mile hydrogen-cell-powered flight from the Orkney Islands of the northern coast of Scotland. This flight is planned to take place by the end of the year.

Hydrogen-cells are becoming increasingly prevalent in the U.K. and Europe. In London, several public transit buses powered by such cells have been implemented. Meanwhile, in Europe, manufacturing firm Alstom is developing a cell-powered bullet train, dubbed the Coradia iLint, capable of hitting 140 kilometers-per-hour while producing only steam and water.

The plane took off on Saturday morning to fly Navalny to Berlin's Charite hospital for treatment
A representational image of a plane. AFP / Dimitar DILKOFF