GE Aerospace has managed to get a plane equipped with hybrid-electric propulsion for the first time exceeds 30,000 feet of altitude, equivalent at about 9,100 meters. The test took this technology up to the usual cruising altitude of commercial aircraft and allowed maintain it for more than two hours on the longest test flight.
The device used was a Saab 340B modified, a turboprop plane designed to carry around 30 passengers, Reuters reports. The original model measures 19.73 meters in length, has 21.44 meters wingspan and can reach a cruising speed of 524 km/h. It is usually powered by two engines. CT7-9B and its operating ceiling is 7,620 metershence The experimental specimen flew much higher than expected for the commercial version.
The modification was concentrated on the right side of the plane, where it was installed the megawatt-class, multi-kilovolt hybrid-electric system developed by GE Aerospace within the program EPFD of the POT. The megawatt class indicates that it can handle power on the order of a million wattsnecessary to move an aircraft of this size. The reference to several kilovolts means that electricity circulates at several thousand voltswhich allows large amounts of energy to be transmitted with less current and lighter wiring, although it requires more complex insulation and cooling systems.
An electric aircraft depends on its electric motors and the energy stored in batteries, whose limited energy density restricts the autonomy and size of the devices. GE solution for modified Saab 340B retains a turbine engine CT7 and combines it with electric motors and generators. The system can distribute the power between both during the different phases of flightemploy electricity to help move the propeller and generate energy to recharge the battery when conditions allow.
The electrical equipment was housed in a ‘inverted gondola’ designed by Aurora Flight Sciencessubsidiary of Boeing. The nacelle is the aerodynamic casing that surrounds the engine and associated systems. In this case it was installed with an inverted arrangement compared to the usual configuration and with additional air inlets to improve ventilation.
The campaign began with evaluation flights carried out in the United States by GE Aerospace pilots and BETA Technologies. The Saab ascended above 9,100 meters and kept the hybrid-electric system active for more than two hours in one of the tests. After crossed the Atlantic to the United Kingdom to participate in the Farnborough Airshow and used hybrid mode in all stages of the trip.
‘The aviation industry’s first high-altitude hybrid-electric flight will go down in the history books’he states H. Lawrence Culp Jr.., president and CEO of GE Aerospace in a statement. The company believes that the trial demonstrates that These systems can operate with reduced atmospheric pressure and the low temperatures typical of commercial routes..
Kyle Clarkfounder and CEO of BETA Technologies, assures that ‘this hybrid-electric system improved high altitude performance and climbing abilitywhile creating a flying laboratory which will serve as a reference for all future hybrid designs.’ Clark adds that the ground and flight tests, culminating in the crossing of the North Atlantic, represent the first of several milestones that the technology must still overcome.
Graham DrozeskiCTO of Aurora Flight Sciences, highlights that the team achieved integrate ‘a high-voltage electrified propulsion system into an aircraft operating at commercial altitudes’. The result brings hybrid propulsion closer to larger aircraftalthough new tests will still be necessary before it can be incorporated into commercial passenger aircraft.