The Pipistrel Panthera is a lightweight, all-composite, highly efficient four-seat aircraft under development by Pipistrel of Slovenia. The gasoline-powered version of the Panthera is intended to cruise at 198 KTAS (366.7 km/h) at FL 080 for over 1,000 nmi (1,852 km) with a 14.8 gph (56 L/h) fuel burn. There are two other versions planned, one with a 145 kW hybrid-electric power system, and the other with a 145 kW pure electric system. These two latter variants will only seat two people to accommodate the electric systems. The company is offering the Panthera as an experimental aircraft, either factory-built or as a kit for amateur construction, with the type certified variant expected in 2022. Development In May 2011, Pipistrel was working on constructing the prototype, powered by the Lycoming engine, with all of the aircraft molds already completed. The first flight was planned for autumn of the same year, with the aircraft being tested the following summer with the electric technologies derived from the Green Flight Challenge electric Taurus project. It should be initially offered in kit form, and Pipistrel indicated that construction will take place in Italy. A test aircraft was presented at AERO Friedrichshafen 2012 in April 2012. On March 29, 2013, the Panthera had its first successful engine start, using a Lycoming engine, and subsequently began taxi tests in preparation for the "complete flight test programme". The Pipistrel Panthera made its 54-minute maiden flight less than one week later on April 4, starting the evaluations of performance, handling and systems in flight. Less than one month later, the Panthera flew over the Alps to the Aero fair at the Friedrichshafen Airport. In March 2014 it was announced that the intended four-cylinder Lycoming IO-390 powerplant will be replaced by a six-cylinder Lycoming IO-540. The change was made due to Lycoming Engines not planning to certify the IO-390 for automotive fuel as an option. The IO-540 will provide the same cruise performance and fuel economy, but weighs more. However, it will allow the Panthera's gross weight to be increased by to make up for the extra weight. The aircraft will use the existing cowling, which was originally designed to accommodate a six-cylinder engine anyway. The EU funded the Hypstair program over three years till 2016: a Panthera mockup received a serial hybrid-electric powertrain, ground testing a 200-kW motor driven by batteries only, by a 100-kW generator-only and by both