A hybrid electric airplane with vertical takeoff and landing capabilities is the next dream child of DARPA, the Defense Advanced Research Projects Agency, and it has just awarded another round of funding to get one such project off the ground. DARPA is the US cutting-edge research funder that birthed the Internet, among other goodies, so let’s take a look and see what makes this thing unique.
DARPA Hearts Hybrid Electric Airplane, With VTOL
Aurora Flight Sciences of Massachusetts unveiled a small-scale electric VTOL aircraft (that’s for vertical takeoff and landing) in 2009 under the moniker Excalibur, and by 2014 the company was receiving DARPA funding to ramp it up to scale and improve its performance.
In the latest development, Aurora announced that has just been awarded Phase 2 funding to continue development of its hybrid electric airplane, dubbed LighteningStrike, under the VTOL X-Plane program. With Aurora at the helm, the team also includes Rolls-Royce and Honeywell.
The aim is to get an increase in speed of about 50 percent over the current crop of VTOL aircraft, among other performance milestones.
First Ever Distributed Hybrid Electric Propulsion System
With Rolls and Honeywell on its team, Aurora is staking claim to the title of first for its propulsion system. The meat consists of a Rolls AE 1107C engine clocking in at 7,000 shaft horsepower, same as the one used by the Marine Corps MV-22 Osprey and Air Force CV-22 Osprey:
The big question is, how to distribute all that horsepower among the aircraft’s 24 ducted fans. That’s where Honeywell comes in. The engine will power three Honeywell generators:
The aircraft’s electric distributed propulsion (EDP) system would consist of highly integrated, distributed ducted fans that, combined with the synchronous electric drive system, would enable the design’s potentially revolutionary hover efficiency and high-speed forward flight.
In addition to sporting what Aurora bills as the first distributed hybrid electric propulsion ducted fans, LighteningStrike is on track to be the first aircraft to demonstrate VTOL with both tilt-wing- and tilt-canard-based propulsion (that’s “canard” as in wing configuration, not a nasty rumor):
Onwards And Upwards For Electric Flight
Aurora doesn’t expect to have LightningStrike up in the air until 2018-ish, so don’t hold your breath, but in the meantime, the US space agency NASA has been digging into the propeller-driven electric aircraft field under the Leading Edge Asynchronous Propeller Technology (LEAPTech) project. The way NASA sees it, electric power will enable lighter, safer, and more efficient aircraft.
The agency’s LEAPTech project puts that theory to the test with the testing of an experimental 31-foot carbon composite wing section, arrayed with 18 motors driven by lithium-iron-phosphate batteries. The wing has been mounted on a truck and driven on the ground for testing, but here’s the plan:
The truck experiment is a precursor to a development of a small X-plane demonstrator proposed under NASA’s Transformative Aeronautics Concepts program. Researchers hope to fly a piloted X-plane within the next couple years after removing the wings and engines from an Italian-built Tecnam P2006T and replacing them with an improved version of the LEAPTech wing and motors.
NASA explains that Frankensteining its new wing onto an existing aircraft enables it to compare the performance of the new wing over the conventional apparatus.
In addition to the potential for charging the batteries with renewable energy, NASA anticipates improved performance and comfort, including noise reduction. When it’s all put together, the NASA electric airplane will look like this:
NASA has its sights set on converting much of the global aircraft fleet to electricity sometime within the next 10 years or so, give or take.
Another NASA electric airplane project is the 2011 Green Flight Challenge, an innovation incubator that focused on fuel efficiency as well as electric propulsion.
For you fuel-cell fans, just last month, CleanTechnica took note of a new airplane that will use onboard fuel cells for taxiing to save on fuel.
As for the here and now, one high-profile example of all-electric flight is the Solar Impulse. The 100% solar-powered aircraft took off on a global demonstration tour last year from the urban sustainability showcase Masdar City.
Images via Aurora Flight Sciences, Rolls-Royce and NASA.