26 | Flight International | 28 January-3 February 2020 flightglobal.comROTORCRAFT
At that point, Kopter was preparing to fly
the programme’s third prototype – effectively
the aircraft to be used to mature the configura-
tion. But because the issue was found to afflict
all of the gearbox components produced, the
only way to get the helicopter into the air was
a significant period of test and evaluation to
prove – to itself and to the European Union
Aviation Safety Agency (EASA) – that flights
with the parts would be safe within a certain
flight envelope.
Then, when EASA had given its permis-
sion for those flights to start – the first sortie
took place in November 2018 – the dramati-
cally reduced envelope meant much slower
headway than expected.DECENT PROGRESS
“The envelope restrictions in terms of air-
speed and manoeuvres were so severe that it
really hampered progress,” says Riccobono.
Nonetheless, with persistence that eventu-
ally translated into “decent progress”, despite
the “limitations of the flawed gearbox”.
But flights were anything but simple.
Take-offs with the “crippled” gearbox were
a “nightmare”, says Riccobono: pilots
were forced to perform an ungainly shuffle
to become airborne without overstressing
the housing.
“You had to suppress your natural reaction.
[The technique] goes against anything
you have been taught,” says test pilot
Michel Dekkers.
Similar restrictions were applied to flight
as well: test pilots describe sorties where
either Riccobono or flight-test engineer
Adam Reynolds were constantly issuingwarnings when approaching speed, altitude
or power thresholds.
Hovering was also ruled out because of the
likely strain this would put through the hous-
ing. “There were several times when I won-
dered whether [flying] was a good idea,” con-
fesses one pilot.
But in September last year, came the “long-
awaited retrofit” of the new gearbox housing,
sourced from a different supplier: “Now we
can fly the helicopter rather than the helicop-
ter flying the pilots,” says Riccobono, “and
explore the full envelope.” But with the first
sortie using the new component only having
taken place last autumn, envelope expansion
work is still in its early stages. Nonetheless,
Riccobono sees that “significant progress” has
been made: weight has been incrementally in-
creased to 2.6t – close to the target of 2.85t –
and the helicopter has been taken to 10,000ft
density altitude.
Test activities have been aided by the estab-
lishment of the dedicated facility in Pozzallo.
Staff undertake six-week rotations at the site,
and the final Sicilian sortie of 2019 – coinci-
dentally the prototype’s 100th – took place on
4 December (the flightplan reads: “conduct a
photo shoot in the vicinity of Modica”).
“[The aircraft] is giving us more than I
could expect – we are really using it now as I
would call it a workhorse in order to get the
final configuration frozen. The pilots are quite
happy with it,” says Lowenstein.
Data gathered from the flights with the new
gearbox housing will be used to inform
improvements to the helicopter that will be
implemented in early 2020. Modifications
include changes to the elastomeric bladedampers on the main rotor head to improve
ride quality, plus an assortment of aerody-
namic and handling tweaks, such as to the
vertical fin and horizontal stabiliser.
Chief test pilot Richard Grant says that the
ride of the SH09 is already as smooth as or
even smoother than other helicopters out
there, although at certain parts of the enve-
lope there are “weaknesses” which “is what
we are working on”.
Approaching top speed “we are seeing a
little bit of motion in the nose”, he says,
which is what some of the changes are de-
signed to counteract.
The final configuration will be reflected in
two further test articles: pre-serial (PS) aircraft
4 and 5, which will arrive from mid-2020.
A substantial amount of certification flying
will be carried out by PS4 in Pozzallo, leading
to an aircraft approved to operate at 16,000ft
density altitude and at temperatures between
-10°C (14°F) and 35°C. That will be followed
by cold weather and hot-and-high campaigns
using PS5, in Alaska and Colorado, respec-
tively, clearing the SH09 to operate at temper-
atures as low as -40°C.
Riccobono says that even without the
changes the SH09 would be certifiable, but
Kopter’s ambition is not to produce an aircraft
that is merely adequate. “We always want to
be better than the others,” he says.
The intention is to be “a little bit above the
EASA certification level”, he says, which
includes having the safety performance of
a CS-29 helicopter – essentially crash-
worthiness and bird strike resistance – in an
aircraft certificated to EASA’s CS-27 small
rotorcraft standard.❯❯Kopter
Mollis facility faces challenging weather
conditions during winter months