Gizmag caught up with William Mannarn and Scott Andrew from EADCO GmbH at the Paris Air Show, and learned that the company recently joined forces with PC Aero to start development of the latter's new twin prop, 6-passenger electric airplane concept called the Elektro E6. EADCO is now busying itself designing the frame for the potentially groundbreaking craft, while PC Aero takes care of the electrical systems.
PC Aero previously designed the smaller Elektra One and Elektra One Solar, which draws about half of its energy for flying from solar cells on the wings.
At the moment, the partnership is aiming to create a plane that is low on noise, vibrations and CO2 emissions, but also capable of over 700 km (435 miles) of range on 400 kg (882 lb) of on-board batteries. However, the designers are hoping that battery technology will continue to improve over the next decade to reach that goal, as the current range feasible from that amount of batteries is closer to 300 km (186 miles).
One possibility that the Elektro Sky team is aware of, but has no direct connection or commitment to, are the new microbatteries developed at the University of Illinois.
The key calculation is that 10 percent of the E6's power needs must be met by on-board solar power, something that's not currently possible with existing technology, according to EADCO, but could soon become reality. The target cruising speed for the plane is 220 km/h (137 mph/120 knots) with a maximum speed of 300 km/h (186 mph/162 knots).
Mannarn stressed that the project will wait for proven and suitable technology, so as to avoid the kind of battery issues (and corresponding groundings and negative press) suffered recently by Boeing.
"There are a lot of companies talking about how they're developing new batteries, but we want to see them, we want to see them in use," says Mannarn. "We want to make sure that we don't have a problem similar to the Boeing problem, with the batteries overheating, catching fire, burning. So clearly the manufacturing processes for these next generation batteries has got to be absolutely precise. The batteries must be safe for use in an aircraft."
The E6 will sport a 16-meter (52-ft) wingspan and a 10-meter (33-ft) long body, and will stand 3.34 meters (11 ft) tall. The fuselage height and width is estimated at 1.4 meters (about 4.5 ft) with two doors at the front and a large passenger/cargo door at the rear.
Though the final frame materials are still to be decided, it seems likely to be carbon fiber composite and lightweight honeycomb construction.
"The key thing is to have the frame available at the time that the technology is ready for implementation, so that our partners don't have to wait seven years designing the aircraft," adds Andrew.
EADCO's Mannarn says that each prop on the E6 will have two electric motors driving it, lowering maintenance costs and being configured in a way that creates "almost a redundancy."
He says they're hoping to have batteries that can recharge in about an hour, but can also be swapped out so that when the E6 reaches its destination, the batteries can be replaced for the next flight.
That's a long to-do list to get the E6 up and flying as envisioned, but the team says it would like to have a working prototype built within the next three years and have a design certified for service within a decade. That design includes fully-retractable landing gear, pressurized cabin, and anti-ice systems.
Have a look at the conceptual video below for an idea of what's currently on the drawing board.
Source: EADCO GmbH
I'd rather warn ProAero not to engage too far into this possibly deceptive joint venture.
The energy density required for batteries in a practical electric plane is an order of magnitude greater than the energy density of kerosene. Batteries do not get lighter as the energy is used.
Not here yet, but time to start designing the airframe.
There will be plenty of time to design the airframe after someone announces a prototype battery of adequate energy density.