2. The cockpit is
roomy with plenty of shoulder
and leg space. The side by side
seats are not adjustable. The
ailerons and elevator are
controlled by a single centrally
mounted stick between the pilots
seats which comes to hand
easily. Dual throttle levers are
fitted to the front of the seats
between the pilots' legs. This
arrangement makes it difficult
to see the exact position of the
throttle setting at a glance.
There is no throttle friction
device. The unusual layout of
stick and throttles quickly
becomes perfectly natural to
use, but for flying instruction
the single centrally mounted
stick could be a disadvantage in
some circumstances. The field of
view is what one might expect
from a high wing monoplane. As
with many high wing monoplanes
it is not possible to see either
above or behind the aircraft. A
65 litre fuel tank is fitted in
the cockpit behind the seats
where the fuel contents can be
seen clearly. Apart from useful
small recesses under the seat
cushions, and side pockets in
the cockpit doors, the only
storage space is behind the
seats around the fuel tank from
which small items could migrate
to the rear fuselage area unless
some form of net or retainer is
fitted.
3. The steerable
nose wheel is operated by moving
the rudder pedals and makes
taxiing straightforward. The
main wheel brakes operate
hydraulically via a hand control
mounted on the central consol. A
wheel brake parking catch is
fitted. When turning on soft
surfaces, with Standard Wheels
fitted, use of the wheel brakes
and nose wheel steering together
tends to make the wheels slide
and the turning radius diameter
is then increased. The normal
minimum turning radius is around
20 ft. Minimum radius turns are
achieved by using nose wheel
steering and careful application
of power without brake
application. The turning radius
in both directions is about the
same The view ahead and to each
side while taxying is virtually
unobstructed. The main wheels
can just be seen with the cabin
doors closed.
4. The flaps
should be set to the first stage
for take off. A gentle swing to
the left on starting the take
off run, due to P effect, is
easily controlled with rudder.
The nose wheel should be raised
at 45 KIAS and the aircraft
flown off at 55 KIAS. Achieve 65
KIAS and when established in the
climb, and at around 200 ft,
raise the flaps and continue the
climb at 72 KIAS. There is a
mild nose up trim change as the
flap retracts. The flap limiting
speed of 70 KIAS can easily be
exceeded, particularly at light
weights.
5. The rate of
roll using the ailerons alone is
relatively slow but the rudder
is powerful and a co-ordinated
turn, using plenty of rudder,
makes for a more respectable
roll rate. Control forces are
pleasantly light with the
elevator and aileron being about
the same for a given deflection.
Rudder forces are about twice
those of the aileron and
elevator. Elevator trim is
achieved by a spring bias
system. At 60 KIAS with full
flap, the trim is fully back and
a slight nose down out of trim
condition remains.
This feature,
combined with the limited up
elevator movement, results in a
certain lack of elevator power
at low IAS which could prevent a
full round out during a
precautionary landing if the
speed were allowed to fall too
low with low power just before
the flare.
6. Longitudinally
the aircraft is very stable both
stick free and stick fixed.
Directional stability is
somewhat weak which means that
considerable attention must be
paid to achieve balanced flight.
The combined lateral and
directional stabilities are
quite satisfactory, although the
rudder does not centralise
quickly on release in a side
slip. The ailerons are not
powerful enough to hold more
than about 15* bank in a
straight side slip. However,
overall, the Jabiru is pleasant
to fly and is not limited in any
way by its stability
characteristics.
7. At the maximum
gross weight of 430 kg the
straight flight power off
stalling speeds (KIAS) are:
Flaps up 54
1st Stage flap 51
Full flap 45
8. At all flap
settings, with idle power,
natural stall warning buffet is
minimal and there is no
significant tendency for a wing
to drop. If the stall is held
with the stick on the back stop
the aircraft gently rolls to the
left into a slow descent. Stall
recovery is immediate on
releasing back stick pressure
and lowering the nose. The
ailerons are effective at the
stall.
9. With flaps
retracted, power at settings up
to full throttle, and right
rudder to maintain balance, the
stall is equally benign and with
the stick on the back stop the
aircraft gently rolls to the
right and enters a spiral dive.
Recovery is immediate on
reducing power, correcting the
yaw, and moving the stick
forward.
10. Accelerated
stalls are also benign, and the
aircraft can be held in a turn
in either direction at full
power just above the stall
without any tendency to roll out
of or into the turn.
11. As mentioned
in para.5, it is not possible to
trim out the nose down moment
with full flap set at 60 KIAS.
In this approach configuration
the trim lever is fully back.
When increasing power in flight
the trim lever tends to move
back.
12. Th
e Jabiru
2200 runs very smoothly in all
phases of flight. Engine noise
in the cockpit is low. Response
to throttle opening is rapid.
Since the engine is air cooled,
and no form of air cooler
shutter is fitted, careful
attention must be paid to
keeping the cylinder head
temperature above the lower
limit when operating at low
power. This is particularly
noticeable during descent. As
the aircraft is very clean
aerodynamically, it is quite
difficult to descend at a
reasonable rate without the CHT
falling below the lower limit of
100*C. The best technique to
achieve a good rate of descent
is to side slip. Extended
taxiing, and use of high power
on the ground, will generate a
risk of high CHTs. For proper
engine care it is important to
study the engine handling advice
contained in the Jabiru Flight
Manual.
13. At the
maximum gross weight, at around
sea level, the take off and
landing performance should
comfortably allow operations
from a grass strip of some 550
metres take off and landing
distance under standard
conditions. However, soft ground
under grass can extend the
length of the take off run and
distance significantly. This
observation is based on the use
of Standard Wheels. BigFoot
wheels, with lower tyre
pressures, are available.
14. The Jabiru
cruises comfortably at 90 KIAS
at 2 -3000 ft using about 2600
rpm. Higher speeds are
practicable if conditions allow
cruising above Va (91 KIAS). The
stability of the Jabiru allows
heading and height to be
maintained in smooth air with
very few control inputs.
15. Apart from
the small residual nose down
moment in the approach
configuration with full flap,
landing the Jabiru is
straightforward in every
respect. The aircraft is very
tolerant and easy to handle in
cross winds up to the maximum of
14 knots. The wing down
technique should be used for
cross wind landings.
16. The Jabiru is
an excellent choice for the kit
builder who wishes to operate a
reliable, strong, easy to fly,
and relatively simple to
construct two-seater with a
performance which can cope with
grass strip operations without
undue difficulty. The machine's
docile flying qualities are
well-suited to the low hours PPL
trained on any of the standard
flying club types, and who
perhaps is not able to fly
particularly frequently. These
qualities are combined in an
aircraft having reasonable
cruising speeds, a comfortable
cockpit, and very modest fuel
consumption. Altogether the
Jabiru is a commendable and
impressive step forward in the
field of kit built aircraft.
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