JANUARY-FEBRUARY 2018 99
battery technology you can already do
something, and do not have to wait for
some kind of completely unexpected
battery technology. With hybrid
technology, you could see it, by 2030,
being large-scale available so that
hybrid-electric aircraft can fly.”
“Any hybrid-electric configuration
requires energy storage to make it
work,” says Airbus’s Cousin. “One of
the benefits that you could envisage
is a downsizing of the gas turbine
and then supplementing it during
the other phases by energy storage.
Today, the most advanced method of
energy storage for aviation would be
batteries. Will that be the case in five
or ten years time? We don’t know, but
yes, energy storage is definitely part of
it, which is why this demonstrator is
built of three elements: the gas turbine
with the generator, the electric turbine
driving a thrust-producing fan, and
a battery system storing energy. It’s a
triangle of energy management.”
Airbus is building on the E-Fan
program as it develops E-Fan X
“We started around 2010 on our
journey of exploring the possibilities
for hybrid-electric propulsion,”
Airbus’s Llewellyn tells Australian
Aviation.
“One of the best-known
demonstrators that we built is E-Fan.
E-Fan crossed the English Channel
in July 2015, and we learned a huge
amount from that project. It was very
successful in teaching us the potential
of electric propulsion as applied to
aviation, and it taught us a lot in terms
of the lessons that we need to learn in
terms of electric propulsion in order to
design bigger and bigger aircraft.”
It’s not just the aviation industry
that is making major advances,
however, Llewellyn says. “In parallel
with our development of these
demonstrators, what we’ve seen in
the car industry is a huge growth
in terms of electric car stock. If
we compare 2010 to 2016, we’ve
basically gone from zero to 2 million
in terms of electric car stock globally.
That has had a huge impact on
the technology which we rely on
in terms of aviation. So we’ve seen
improvements in performance, we’ve
seen improvements in power density
of power electronics, of electric motors
and electric generators. And that has
allowed companies like Siemens in
2016 to fly the Siemens Extra 330,
which is an aerobatic aircraft, and it
has roughly five times the power of
what our E-Fan had in 2015 when it
crossed the Channel.”
As far as airlines go, “We haven’t
had official discussions with them,
but there are a number of airlines
who are very interested in the
development of this technology, and
when it might be feasible to replace
some of their smaller aircraft that
they operate today with electric or
hybrid-electric vehicles,” Airbus’s
Mark Cousin says.
“Some airlines have already
signed agreements with startups in
this business. There are a couple of
startups in the US, so the interest is
quite high. I think that interest will
grow dramatically as they start to
understand the technology. I already
have two requests to go and explain
to certain of our airline customers the
potential of this technology for the
future.”Beyond airlines, Airbus is also
working on making flying cars a
reality
Urban air mobility “is an adventure
which has already started for us,”
Llewellyn says. “We plan to fly our
first urban air mobility vehicle called
Vahana this year –it’s a one-seat
demonstrator. It’s got eight electric
motors, eight propellers, it’s got a
tilt-wing, and it is being built in our
A^3 Silicon Valley facility in the US.”
“Next year we will have the first
flight of a four-seat demonstrator,
the City Airbus, with a different
type of architecture at the vehicle
level. And those demonstrators form
the backbone for our technology
demonstration for the urban air
mobility market segment,” Llewellyn
summarises.
“There are obviously technical
challenges that we need to overcome,
and that’s why we’re building the
vehicles and we want to demonstrate
the technology. Some of the biggest
challenges we need to overcome are
about air traffic management and
regulation,” Llewellyn notes, andindeed there are major concerns
about safety and a variety of types of
environmental impact on larger cities
in particular.
“We’re going to have these vehicles
flying in cities – they’re going to be
much more local to people in order to
serve the populations that are going
to really benefit from them. That will
require quite significant working
together between the regulators and
the operators and manufacturers
of these vehicles in order for urban
air mobility to really have a positive
impact on society.
“There are already cities where
we have seen a benefit from this
type of concept. We have a project
already piloted in South America
where we’re looking at facilitating the
transportation in São Paulo. We’re
already piloting the urban air mobility
concept by using Airbus helicopters.
That is showing us that already today,
in certain cities, we’re at the point
of saturation in terms of ground
transportation. There is already
a market for urban air mobility,”
Llewellyn says.
Cities the size of Sydney, Hong
Kong, or London “are for sure
candidates for this kind of societal
benefit”, Llewellyn says, “I think the
simple fact that with urban air mobility
we’re talking about using a three-
dimensional space means that it will be
much more capable of absorbing traffic
than the 2D space which is our current
road network system.”
Regulators will have to be
persuaded, of course, for this even
more than a hybrid-electric system
for regional jets, and of course
within those regulators – as within
the industry more widely – a major
upskilling will be required. The
government agencies dedicated
to keeping aviation safe even as
manufacturers push the boundaries of
technology may well see some of the
toughest challenges of all.‘There are
a number
of airlines
who are very
interested.’
MARK COUSINA concept drawing of Airbus’s
battery-powered Vahana ‘urban
air mobility vehicle’.AIRBUS