JANUARY-FEBRUARY 2018 97
in 2010,” Cousin says, “through to our
most recent project, which was the
demonstrator E-Fan 1, which we stopped
earlier this year. We didn’t stop it because
it was not a success: we decided that we
needed to be more ambitious because the
world and the technology in this area is
moving so fast.”
The E-Fan has been an airshow
favourite since its début, not least
because of the future technology that
it represents. Now, it’s getting a next
generation.
“We’ve been working for the last
six months with our two partners,
Siemens and Rolls-Royce, in putting
together an ambitious hybrid flight
demonstrator to demonstrate a two
megawatt propulsion chain in a
regional aircraft,” Cousin explains.
“The objective of this demonstrator
is not to produce a product, but just
to mature technology which will be
the basis of products in the future.
What we plan to do is produce a
demonstrator with a two megawatt
propulsion system, comprising a gas
turbine with an integrated generator
produced by our partners from Rolls-
Royce, a two megawatt motor driving
a propulsion fan produced by Siemens,
and the whole system integrated with
a two megawatt battery and control
system produced by Airbus.”
“We’ve provisionally selected the
BAe 146 as the platform for this
electric motor would help to propel an
airplane,” Siemens’ Anton elaborates.
This is indeed at the cutting edge
of technology, and it is unpredictable
how well the various technologies
will evolve during what is a very short
timescale, so demonstrating using a
single engine initially seems sensible.
“The propulsive force will be a
Rolls-Royce AE2100 engine, the
engine that powers the Lockheed
Hercules,” Rolls-Royce’s chief
technology officer Paul Stein explains.
The engine will be “driving an
integrated generator that we build
within the overall envelope of the gas
turbine, in fact producing two and
a half megawatts – a little bit more
for spare. The power electronics will
convert that power output, which
we believe will be the world’s most
powerful flying generator, into 3,000
volts DC to distribute to the aircraft.”
“Then the actual propulsive fan
is an AE3007 off one of our regional
jets,” Stein says. “We’re taking the fan
off of the regional jet, mating it to the
Siemens motor, and that will fit within
the nacelle of the inner starboard
engine of the BAe 146.”
“The AE2100 gas turbine will be
mounted in the rear fuselage of the
passenger cabin in the BAe 146, with
a dedicated inlet and exhaust, to feed
that gas turbine,” Airbus’s Cousin says.
“The two megawatt battery system,demonstrator,” Cousin says, “mainly
because it’s a four-engine aircraft with
a suitably-sized gas turbine engine
that we can replace directly with an
electric motor.”Four engines for hybrid-electric as the
trusty BAe 146 plays a testbed role
The distinctive high-winged four-
engined BAe 146 regional jet, which
was later developed into the Avro RJ,
will of course be familiar to observers
of Australian aviation, especially in
rural and remote areas. Why the 146?
“What we want to do is replace the
gas turbine with an electric motor,”
Cousin says, “so we need an aircraft
with engines that were about the right
size to require about a two megawatt
propulsion unit, and we also needed
four-engine aircraft for safety reasons.
So the BAe 146 is really the only
platform that meets that requirement,
and it’s just a good platform for the
purpose.”
“We’ll replace initially one engine,”
Cousin explains. “We’ll make provision
for replacing another engine in the
future, but that will depend on how
the initial testing goes.
“Our intention is to replace one of
the test plane’s four jet turbines with
a 2MW electric propulsion system in
time for the maiden flight, which is
scheduled for 2020. That would be
the first time that such a powerful‘We are not
betting on
batteries, we
are betting on
the hybrid.’
DR FRANK ANTONThe Airbus E-Fan demonstrator
crossed the English Channel in
July 2015.AIRBUS