ATL with its JPX engine flew with only 56 hp, after all. Like the ATL, the
Yuneec has a V-tail but a configuration that is lighter and produces less drag
than more traditional cruciform setups. Everything’s a compromise, however, and a V-tail empennage requires a stronger structure and a more
complex control system.
The rest of the airplane, one of five prototypes built so far, shows off the
advantages of composite manufacture: sleek compound curves built into a
strong, lightweight structure. If the overall look of the fuselage is reminiscent
of a motorglider, the undercarriage isn’t. The undercarriage has semi-cantile-ver mains and a nose wheel. It has been designed to appeal to the
flight-training market. I notice that the nose wheel on this model is different
from the aircraft that I’d seen at Oshkosh, in that it’s not braced. Olivier and
his business partner Pierre wanted a simpler, less rigid structure and replaced
the original nose wheel with this more basic version. It proved not to be a
complete success and will soon be replaced by the original. In the meantime,
the development nose wheel has put an end to all but solo flight, so I’ll be
alone for my flight and only the fifth pilot to fly a Yuneec e430.
Before flying I talk to Olivier and Pierre about the airplane and, more
importantly, its motor. Not only is Yuneec building what looks like the first commercially available electric airplane, but the company has designed the motor
and builds it in-house. The Power Drive 40 is a brushless motor that delivers 40
k W of power. It weighs in at 42 pounds and will take between 100 and 150 volts,
and there’s an electronic control unit that sits under the left rudder pedal.
The DUC propeller is ground-adjustable, so in theory the prop pitch can
be set to match the mission while on the ground. The carbon-fiber spinner
has air inlets to help to keep the motor cool. Given the weight of the battery
alone, there’s no doubt that an equivalent fossil-fuel airplane would have a
significantly greater endurance. It would, of course, also have a higher direct
operating cost, and at today’s prices, Olivier estimates that an hour’s flight
would cost in the region of € 1. 40. That’s impressive, but there are other things
to take into account with electric airplanes, and while the motor is pretty
maintenance-free (only the bearings need changing from time to time), the
battery is good for 3,000 hours, after which it’ll need changing at a cost of
about € 15,000, so add € 5 an hour for your battery fund.
SILENCE IS GOLDEN
I expect to find a standard prototype cockpit, full of odd wires, fixings, and
other bits not quite ticked off the to-do list. As I lower myself into the
Length: 22 feet, 11 inches
Wingspan: 45 feet, 3 inches
Height: 8 feet, 8 inches
Empty Weight: 650 pounds
(including battery & BRS parachute)
Powerplant Make & Model:
Yuneec Power Drive 40
Output: 40 k W ( 54 hp)
Weight: 51 pounds
Flying time: 2 hours
leather seat I am pleasantly surprised. There may be
one or two things to fine-tune with the canopy, but the
cockpit is pretty much established, and I find myself
settling into a position that is reminiscent of Diamond’s
DA20 Katana. The seats are fixed, with the rudder
pedals adjustable by means of a handle near my knees.
Ahead, there’s the flap lever, the elevator trim, and the
power lever. Otherwise there are a few switches, a
temporarily non-functioning Dynon, a Yuneec screen
giving battery state information, a Garmin 496, some
analog backup instruments, and not much else. The
lack of both a compass and the Dynon is no great
concern for what will be a local flight.
I buckle up, close the canopy, sit back, and
familiarize myself with the cockpit. There’s a lot less
stuff than you’d find in a normal airplane. No key, no
mag switches, no fuel tank selector, no fuel tank
gauges, no EGT or CHT displays, no temperature and
pressure for oil, and no cowl flaps. Instead, there’s a
master switch, a big fuse, and a digital monitor that
provides you with information on the temperatures of
the motor, power controller and the battery voltage,
the percentage power, the real-time discharge rate,
the rpm, and the power being delivered, in both k W
and hp.
After a full brief from Olivier, I now find myself
alone and ready to start. Obviously there isn’t really
a start as such; when the power lever is closed the
propeller isn’t moving and there’s no noise. It’s a bit
like sitting in a hybrid car at traffic lights. Once you
push the power lever forward, however, things start to
happen. The sound is similar to a turbine start before
the fuel is injected. The DUC prop turns immediately,
and the airplane moves forward.
I find the airplane easy to taxi, particularly with
its effective disc brakes (steering is by differential
braking), but what is most surprising is the quietness
and complete absence of vibration.
