AEROSPACE SUPPLEMENT
ELECTRIC DREAMS BECOMING REALITY
Charged & ready
While electric cars are today a reality, albeit we will see many further
strides yet in the development of that technology, the aerospace
industry has a larger challenge and is still early into its journey.
Andrew Allcock offers this snapshot
The ever-ebullient and publicity-friendly
Elon Musk of electric car maker Tesla
fame was reported by online organ
Electrek (https://is.gd/axirol) in July this year
as saying that electric aircraft would be put
into use within ve years. He already has a
design for an electric vertical take-off and
landing aircraft, in fact. But battery technology
must improve, he adds, saying that Li-Ion
batteries need to achieve a 400 Wh/kg energy
density in order for batteries to best kerosene
and make his electric aircraft viable. Today,
high cycling battery cells are achieving about
300 Wh/kg of energy density, the article adds.
It should be said that Musk has not yet
said that his company is going to produce such
a plane, however, or revealed much detail
about the design. It is likely that it is one of
the many small, personal or taxi-type electric
aircraft currently being developed. According to
an article on the Royal Aeronautical Society’s
website published in December 2017 (https://
is.gd/elitun), there were some 300+ start-ups
and established companies active in that area
even then.
A little bit larger in scale and in June this
year, US rm Ampaire’s hybrid-electric Cessna
337 Skymaster made its rst test ight. The
aircraft is a six-seater typically powered by twin
210 hp engines. Ampaire replaced one engine
(the rear unit) with an electric motor, creating a
system in which the two propulsion devices
work in concert (video: https://is.gd/upemir).
Ampaire says it plans to establish a pilot
programme with Mokulele Airlines on a short
commercial route on the Hawaiian island of
Maui, using another retro tted Cessna 337,
later this year. The company is also
establishing a pilot programme with Puerto
Rican regional operator Vieques Air Link and
Ampaire says it has signed letters of interest
with 14 other airlines around the world.
Going up in scale a bit more and United
Technologies Corp (UTC) recently unveiled its
hybrid-electric ight demonstrator, Project 804.
Its goal is to re-engine and y a regional turboprop
aircraft powered by a 2 MW hybrid-electric
propulsion system. A twin turbo-prop
Bombardier Dash-8 (19 passengers) with a
2 MW hybrid-electric powertrain will be the
subject aircraft. The project’s group combines
the engineering expertise and experience of
UTC companies Collins Aerospace and Pratt &
Whitney, plus the company’s research centre.
To support this effort, Collins
Aerospace is making a $50m
investment in a lab as part of a larger $150m
total investment it expects to make in electric
systems over the next three years and builds
on the $3 billion it says it has spent on
advancing its electric architectures over the
past decade. Work on the 25,000-ft2 lab,
called The Grid (video: https://is.gd/ogasif) is
already underway in Rockford, Illinois, with the
project expected to be complete and fully
operational by 2021.
Collins Aerospace will use The Grid to help
design and test a 1 MW motor, motor
controller and battery system in support
Project 804. The 1 MW motor will, says the
www.machinery.co.uk @MachineryTweets October 2019 9
Airbus
Rolls-Royce and Airbus
are working together on
the E-Fan X project
/axirol)
/upemir)
/ogasif)
/www.machinery.co.uk