Stuttgart, Germany -- Last September 29, Thursday, German aircraft engineers successfully carried out a 10-minute test flight at the Stuttgart Airport, Southwestern Germany. The flight, involving two real human pilots and two dummy passengers lasted up in the air for about 10 minutes.

Stuff NZ says that the twin-cabin plane, also known by the name the HY4, was developed by aircraft maker Pipistrel, fuel cell specialist company Hydrogenics, the University of Ulm in Southern Germany, and the German Aerospace Center DLR (Deutsche Zentrum für Luft- und Raumfahrt).

Fuel cells are a known, yet underutilized energy source for transportation. These fuel cells use hydrogen and chemical processes to generate electricity while the plane is in-flight. This allows the plane to fly at speeds of up to 165km per hour and reaching a range of up to 1500km.

New Atlas gives us a closer look on the technology behind the fuel-cell plane: "The HY4's 21.36 m (70 ft) wing is home to the HY4's central single propeller with a two-seater fuselage on either side, a design that's said to allow for "optimal distribution of the drive components and a higher total loading capacity." Each fuselage is home to a 9 kg (20 lb) hydrogen storage tank that feeds the four low temperature Proton Exchange Membrane fuel cell modules sat behind the prop. These cells convert hydrogen and oxygen into water and electrical energy."

Boeing and Airbus, two of the biggest aerospace manufacturers in the world, have been testing smaller fuel cell plane prototypes throughout the years. This technology is seen to create quieter aircraft, and more importantly, does not release any harmful emissions from the energy released. In addition, take-off and landing, some of the most fuel-consumptive parts of flying, is powered by batteries, which can easily be recharged or replaced in case of damage or maintenance.