Flight International - 04

Programme Development
County International airport. During
that 8min flight, the aircraft climbed
to 3,500ft and flew at 160kt – and
Eviation collected “terabytes” of
performance data, Davis says.
Since that first – and still only
– flight, the company has been
evaluating the aircraft’s in-flight
performance, and comparing the
data to expectations. “We’ve had
very good correlation,” Davis says.
“The aircraft performed very closely
to how we modelled it.”
Long-term partners
Eviation will soon disclose more
suppliers. “Most of our focus right
now is… figuring out who’s going to
be the long-term partner suppliers
for the production aircraft,” Davis
says. “You are going to see major
supplier announcements.”
The company has previously
named several suppliers that
worked early on the Alice programme.
GKN Aerospace was manufacturing
wings, empennages and
wiring systems, Honeywell Aerospace
had worked on cooling and
fly-by-wire systems, South Korea’s
Kokam was an early battery supplier,
and Parker Aerospace was
named as suppling cockpit controls,
hydraulics and flap and thermal
management systems.
Because Eviation’s expertise lies
in “electric aircraft design [and]
systems integration” – rather than,
say, composites manufacturing –
its production plan involves significant
outsourcing.
“We’re going to find the best
available supplier for each of the
systems on the aircraft, and we’re
going to use them to help us
integrate the airplane,” Davis says,
adding that Eviation itself will
complete the assembly.
Which company will first operate
Alice remains unclear, but
Massachusetts-based commuter
airline Cape Air is a leading candidate,
having been among the first
to commit to purchasing the type.
The carrier signed a letter of intent
to acquire 75 of the aircraft.
Eviation has now “sold” more
than 300 aircraft, Davis says,
though he declines to specify sales
prices or other details. Some aerospace
analysts say purchase agreements
involving conceptual aircraft
often involve minimal actual money
changing hands – but Davis insists
the agreements are solid: “They are
real orders or very strong expressions
of interest.”
Aside from Cape Air, Mexican
start-up airline Aerus, Air New
Zealand, Australia’s Northern Territory
Air Services, Germany’s Evia
Aero, DHL and US carrier Global
Crossing Airlines have committed
to acquiring Alice.
“These are legitimate airlines
today that are flying short-haul
routes,” Michaels notes.
Alice will likely be recharged
using connectors similar to the
“Combined Charging System” used
widely by the automotive industry,
Davis says, adding that Eviation has
already installed two such systems,
at Moses Lake and Arlington.
Roughly 30min of charging
should provide enough power for
about 1h of flight, and operators
can expect to replace Alice’s batteries
after 3,000h of operation, he
says. “We’ve designed the batteries
with a finite lifecycle so we can
operate with a 30min charge.”
Company will seek to certificate aircraft as
commuter type under existing FAA regulations
Eviation’s earlier round of funding
enabled it to develop the technology
behind Alice and to bring
the aircraft through first flight. “We
are now in the middle of our next
funding round,” Davis says.
He declines to be specific about
Eviation’s financial situation or to
reveal the anticipated cost of developing
and certificating Alice, but
says the expense should be comparable
to that of developing conventionally-powered
commuter aircraft.
AeroDynamic aerospace analyst
Glenn McDonald estimates that
developing and certificating an
aircraft under Part 23 should
cost “much less than” $1 billion.
Based on Alice’s business case,
“development costs can’t be more
than the several-hundred-million
range if the aircraft programme is
going to have an overall positive
return”, he says.
Battery lessons
Completing the first flight suggested
Eviation has recovered from a
setback in January 2020, when another
prototype was destroyed by
fire while on the ground in Prescott,
Arizona. That aircraft’s lithium-ion
batteries ignited due to a “thermal
runaway event”, Davis says.
He calls the incident a “learning
experience” that “certainly
changed the way we approached
things”, prompting Eviation to improve
Alice’s battery management
system. The event also “helped
formulate how we [are] going to
certify and produce safe batteries”.
Following the fire, Eviation
commissioned an accident investigation
that culminated in a several-hundred-page
safety report,
which the company shared with
the FAA and US National Transportation
Safety Board, Davis says.
The report highlighted the “importance
of being able to… monitor
the aircraft battery systems down
to the individual cell level”, he
notes. “We have built that sensor
technology into our battery.”
Alice now has a battery management
system that can control
and “isolate” the individual “subpacks”,
which each contribute
about 1% of total power.
“That will stop a repeat of the
event that we saw,” Davis says,
noting that Alice can continue to
fly safely even if the system shuts
down some of the sub-packs.
“Now we know what we need to
watch out for.” ◗
April 2023 Flight International 33