eFlight Journal 02-2020

e Aviation Talk
Pipistrel’s
eVTOL design
concept.
There
will be
manned and
unmanned
Aircraft with
a similar
concept.
the working temperature of battery cells on Alpha Electro
is limited to -5° Celsius which is translated roughly into
-15° Celsius ambient temperature.
eFJ: Do you - Pipistrel - produce the battery packing
by yourself?
Tine: Yes, Pipistrel designs and produces all electric
components in-house including the battery packing.
eFJ: Does Pipistrel provide other aircraft OEM the
electric propulsion unit as a complete package?
Tine: The short answer is yes. Because the motor is certified,
OEM just needs to conduct the integration certification
like any other engine installation. As for the battery,
the OEM may go to the regulator to certify the battery
with their airframe because there is no stand-alone type
certification nor TSO specification yet for the battery so
the battery does not carry type certificate itself. We are in
active discussion with EASA for issues like this. Besides
batteries, we are also discussing with EASA for the separate
certification for other components such as BMS.
However if the aircraft OEM decides to use the same
batteries as Velis, the certification process will likely be
much shortened. It is worth noting that the battery packs
on Velis are designed to be a stand-alone component so
when EASA can certify batteries, the battery packs on
Velis can be certified as a separate component and thus
can also be upgraded.
eFJ: Where do you see the battery capacity on pack
level now and in five years?
Tine: Currently we have 180 WH at pack level on the Velis.
To better understand the situation, it’s important to
know many Velis pilots will use the airplane for flight training
operation so affordability and cost are important factors
in consideration of battery use. There are indeed
some battery cells in the market with higher capacity but
they are not economical to operate and to certify. Practically
speaking the pack density may increase 50 % in ten
years and probably 25 % in five years and such batteries
become commercially available for customers by then.
Remember that it takes about one and half years to certify
the battery when it’s commercially available. The aging
test alone takes a minimum of nine months and you simply
cannot accelerate certain process like that.
eFJ: Will the Alpha Electro come to the German market,
or will Pipistrel certify a Velis alike model for the
600 kg category ultralight for Germany?
Tine: The German ultralight regulation requires a maximum
empty weight of 400 kg. Velis, with all the safety
components required by the certification, is a little over
this limit. We are currently carefully studying the option of
removing certain components to lower the empty weight
as well as the price while maintaining the safety of the
airplane. In addition, we can also offer a model called Alpha
Electro LC (liquid cooled) which combines the Alpha
Electro ultralight’s motor with the battery and electrical
system from Velis for other markets with 600 kg regulation.
So we will have three models with similar configuration
to meet different regulation and market demand: Alpha
Electro ultralight, Alpha Electro LC and the certified
Velis which can be used for commercial operation and
EASA private pilot training. Everything considered, Velis
is actually a very competitive model for German market
because when considering the battery as the “fuel” is all
prepaid and the motor’s TBO hours, Velis’ price and operational
cost are very competitive.
24 e Flight Journal
2 / 2020