Aerochute Dual

Transcription

Aerochute Dual
Flight test
Up
& over
from
Down Under
David Bremner
braves a freezing
English December to
try out the Aerochute
Dual paraplane. It
turns out this Aussie
newcomer has
sunshine in its soul
22
Microlight Flying
T
he 450kg microlight weight limit has allowed
an influx of sophisticated designs. We’ve been
seduced by ever-sexier models from France,
Germany and the Ukraine – with a smattering
of English roses too – many of which were showing
off their attractions at SPLASH in November.
So it came as something of a surprise to find ourselves heading down the motorway to look at the
Aerochute Dual paraplane, which could under no
circumstances be described as sexy, is (by modern
standards) slow, and isn’t even new – the same design
has been available since 1992. For a time paraplanes
were very popular in the UK – there was even a UK
manufacturer, Powerchute, whose Kestrel design
looked remarkably similar to the Aerochute – but at
the end of the ’90s the market dropped off and things
have gone very quiet.
So what’s the attraction now?
The answer, judging by the comments from the
long queue of those who wanted to try this type of
flying on a bitterly cold day in early December, is simplicity. For those who are new to aviation, it’s the simplicity of the controls, and the reduced requirements
for a licence. For those who already have a licence, it’s
the simplicity of storage and rigging that persuaded
them that this is the way to go. By the end of the day
I could see what they were on about.
Kiss kiss
Stephen Conte designed the Aerochute in Australia
way back in 1992, using the UK’s BCAR S as a design
standard. Since then he reckons he’s sold about 400
aircraft all over the world, gained approval from the
Australian and British authorities, and says there’s
never been a fatal accident on one of his machines.
Stephen had flown from the warmth of an Australian summer to the coldest UK December for 30 years
to visit SPLASH in support of importer Powerchute
UK, in the persons of Wayne Kimberlin and Richard
Watkin, and to give demonstration flights. Greater
love…
The Aerochute design is based firmly on the
KISS principle (keep it simple, stupid). While most
paraplanes use an open structure, the Aerochute is
positively minimalist, with aluminium tubes bolted
together using short channel sections, just like in the
good old days. The top plate, to which the lines are
attached, and the engine mounts, are welded steel,
but that’s it. Even the propeller shroud, which is circular on most types, is made from straight elements.
The wheelbarrow wheels have no brakes or steering,
and the side-by-side bench makes the seating arrangements simpler – and more friendly too.
While it may not look too slick, it’s very well tried
and very easy to repair. And there are other advantages, as I came to understand as the day went on.
The basic layout is a side-by-side two-seat pusher
trike unit, with an inverted pusher twin-carb Rotax
503 driving a three-blade Ivoprop. The roll cage also
serves to keep the lines out of the propeller. The
bench seat has two sets of four-point harnesses. The
only controls are a single, central T-bar foot throttle,
and toggles which pull the trailing edge of the wing
“
w
Just drive
to where
you want
to fly,
unpack,
make the
most of the
daylight
and drive
home.
Time to
rethink
what we
want from
our flying?
“
February 2009
23
Flight test
wdown on each side.
The wing, a basic 15-cell rectangular design, is
made in-house of zero-porosity ripstop nylon that’s
UV- and silicon-coated. It’s attached via a mass of
lines to four eyes on the top plate. Stephen says that
over the years they’ve tried seven different canopies
for the Aerochute, including semi-elliptical and flattop types, but the current 34m­2 design gives the best
overall performance; it’s the most stable, the most
easy to handle, and it won’t stall. In fact, as the Australians put it, ‘No worries, mate.’
Comfortable two-up
On the day we flew it was around 0°C, with a light
(maybe 5mph) westerly breeze blowing across the
field. We had a total distance from the takeoff point
to the trees at the far side of no more than 150m.
Paraplanes must take off exactly into wind, so
before rigging Richard and Wayne carefully checked
the wind direction. They pushed the Aerochute to
the takeoff point and warmed up the engine. It’s a recoil start (there are no electrics), simple and relatively
safe – provided you remember to chock the wheels.
Once they were happy with the engine they shut
it down and unpacked the wing from its storage bag
on the seat, laying it out carefully in a curve behind
the trike. The lines must be just taut, and the leading
edge should be on top of the rest of the wing pointing
upwards. There’s no need to detach the wing from
the trike in normal use, so you shouldn’t get tangles.
Getting in was simpler than in most aircraft,
though granny might want a hand up and down
from the very low seat. Once in, there was sufficient
space for two, and you don’t feel in any way crowded.
Stephen is built like a whippet but I’m certainly not,
and both of us were dressed for the very, very cold
weather! The four-point belts are very secure, though
the seat geometry makes it important to get the lap
strap as snug as possible, otherwise there’s a possibility of slipping out underneath it. The machine is
rated for a generous combined seat load of 200kg.
Your feet rest in a netting well. It feels odd without
the normal pedals to rest them on.
Stephen started his preflight checks. I was surprised that he didn’t get the engine running first, but
quickly cottoned on to the fact that running it would
inflate the canopy, and we weren’t ready for that yet!
Once he’d done his checks, Stephen surprised
me again by turning to face me. He placed his outside foot on the throttle bar, with his inside foot over
mine. Lesser men than I might have had wondered
about his motives, but the reason quickly became
clear. He asked Richard Watkin to start the engine
and immediately ran it up to maybe half power, look-
24
Microlight Flying
ing over his shoulder to check the inflation of the
canopy, and using the brake toggles to try to ensure
it inflated evenly and directly overhead. The machine
trickled forward while this was happening, and the
non-steerable nosewheel made sure it didn’t go anywhere unexpected while Stephen’s back was turned.
Once he was happy it was right, he faced the front
and opened the throttle fully, and we were off almost
immediately, with no control inputs required.
After the flight was over, I paced out the wheel
tracks in the frost and the whole process took less
“
Stephen turned to face me,
placing his outside foot on the
throttle bar and his inside foot
over mine. Lesser men might
have questioned his motives…
than 50m.
“
Slowly as she goes
For those of us brought up on more conventional
types of aircraft, the natural tendency at this instant
is to eyeball the ASI, but there is no ASI. Don’t panic.
A paraplane is only capable of one speed, so there’d
be no point in having one. Basically, once you’re clear
of the ground, you’re flying at a safe speed as determined by the geometry of the set-up.
We settled into the climb, and I checked my
VSI which was registering about 320ft/min; given
the high drag of the wing and the fact that we were
relatively close to the maximum all up weight, this
seemed about right, although the Aerochute website
reckons you can get 1000ft/min in the right circumstances – ie solo flight, probably flown by a jockey.
We ran speed checks against the GPS, which gave
38mph, tying in exactly with the Aerochute figure of
60-70kph. Stephen says you can alter the speed a little by sticking your feet as far forward as possible.
Then Stephen handed over control. The T-bar
throttle is admirably suited to dual control and I had
no trouble maintaining the power setting I wanted.
Turns are established by pulling on the relevant toggle; there’s a knot to limit the travel. They are very
different from flexwing or three-axis controls, and
you need a good positive hoick to have a significant
effect. Once you’ve readjusted your expectations, w
“
The Aerochute is
positively minimalist, with
aluminium tubes bolted
together using short
channel sections –
just like in the
good old days
“
February 2009
25
Many American
paraplanes use foot
controls for steering
but the Aerochute
has toggles, which
will feel more
natural to anyone
from a paramotor
background
w
“
Toggles are very different from flexwing
or three-axis controls. You need a good
positive hoick to have a significant
effect
“
w control is very straightforward, and the enormous
pendulum stability means that not only do things
happen reasonably slowly, but it’s impossible to get
into radical attitudes.
The view, of course, is fantastic. We took the airto-air photographs from a second machine, and the
clear access pretty much anywhere ahead of us was
unparalleled. Of course, at 60kph you’re not going to
get anywhere very fast, but it’s more than adequate for
local flying. The air was cold and entirely turbulencefree, and the ride was very comfortable, although the
trike ‘nodded’ gently – transferring weight slightly
between front and back risers. It was only just perceptible, and not at all unsettling. Because of the pendulum effect, turns require slightly more anticipation
than on three-axis or flexwing aircraft; it’s a bit like
being on a fairground ride as you swing into the turn,
and the same sense of delight too. Changes of power
also involve swinging gently backwards or forwards,
but the swings were very well damped in both directions. The noise levels are pretty much identical to
those in a 503-powered flexwing, as you’d expect;
not as good as an enclosed three-axis machine, but
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Microlight Flying
no problem with a decent intercom and headsets.
Easy touchdown
It was time to check out the landing. For most of us,
a 150m field with trees at both ends would be a considerable challenge, but Stephen used a powered approach to slip over the tall hedge at the downwind
end, pulling hard on both toggles to flare when a foot
or so from the ground. He trod on the throttle again,
and we easily completed a touch and go in that small
space. Amazing!
Even more amazing – he was proposing to let me
have a go.
Now, suddenly, that field looked absurdly small. I
completed a suitably small circuit and lined up. The
trees at both ends would have made it unthinkable in
pretty much any other machine, but the glide ratio of
4 or 4.5 to 1 makes it pretty straightforward.
I was concerned that such a steep approach would
require some anticipation when flaring, but that
doesn’t seem to be the case. My theory is that when
your eyes are at the normal height for flaring, the
wheels are significantly higher (because you’re sat so
low) and the one compensates for the other. But don’t
quote me…
The landing speed is very low, so there’s no need
for suspension or brakes. We opened up again and I
had another go, to make sure it wasn’t a fluke, and
it wasn’t. This is a very straightforward plane to fly
and to land.
The glide is very steep – a glide ratio of 4.5:1 is
quoted – but the sink rate is only around 750ft/min
because of the relatively low airspeed. So although
Flight test
the area from which to choose an emergency landing
field is small, the size of space you’d need is much
smaller, and it’s much easier to judge a deadstick
landing.
Next time, it was a full stop landing and, as we
rolled to a halt, Stephen pulled very firmly on one
toggle to deflate the wing over to one side. Done correctly, it subsides gently on top of itself, and is pretty
much gathered up together ready to be pulled back to
the take off point.
Less is more
Stephen jumped straight back in for the next demonstration, while I gathered my thoughts about this
amazing piece of kit. All put away on the trailer, it’s
smaller than any other wheeled microlight – it should
fit on the smallest front lawn, or in the back of most
garages without difficulty.
It’s light enough to be towed by even the smallest
car. You drive to your chosen field, which might be
round the corner, or in France, (and doesn’t need to
be a regular airstrip in either case) and rig – which
takes less than 10 minutes and can be done on your
own. The preflight is incredibly simple and after that
you’re in the air. (Sharp-eyed readers may have spotted that the starter can’t be reached from the seat, but
Stephen assures me they can fit an extra pulley on
the top plate). Sure, the 29 litre tank (which should
give you 1.5h safe endurance with 20-30min spare)
won’t get you enormous distances, but the aircraft’s
transportability makes up for that, if all you want to
do is enjoy the view from the air.
One other remarkable fact about this aircraft – it’s
the only two-seater to meet the requirements of the
deregulated sub-115kg sector. You’d need to alter the
seat belts to make it clearly a single-seater, and you
wouldn’t be able to convert it back to a two-seater,
but it’s an interesting thought…
This simplicity of operation was what had drawn
at least one of those in the queue for a demonstration
flight. Having got his NPPL(M), he’d looked at the
time and cost to operate a modern flexwing, and decided this was the way to go. And at £13,225 (at the
current VAT rate) the capital outlay’s a lot lower too,
so it’s hard to argue with him.
w
“
Your feet sit in a netting well. It feels
odd without the normal pedals to
rest them on
w
“
February 2009
27
Flight test
“
One drawback is the relatively light
winds that the Aerochute can manage.
If the wind starts to pick up the corners
of the wing when it’s laid out for takeoff,
it’s time to pack up. This is primarily a
morning-and-evening aircraft
“
w
These are the pros. What about the cons?
Time for a rethink?
The first con is the intolerance of crosswind conditions, which makes it less easy to operate from a
busy strip with conventional circuit traffic, (though
it might be possible to come to a local arrangement),
or a narrow field.
The second is the relatively light winds it can
manage. Stephen told me that if the wind starts to
pick up the corners of the wing when it’s laid out for
takeoff (say around 15mph), it’s time to pack up. This
is primarily a morning-and-evening aircraft.
The third is (we hope) a temporary one; there are
at present no BMAA inspectors capable of inspecting
the wing, and few check pilots cleared to fly them,
which means the annual inspection will be a little more involved than usual, requiring a specialist
BMAA inspector for the trike, a BPA rigger for the
wing, and a specialist check pilot, but Powerchute
will be able to advise you on this and it seems very
likely that as interest in this type of flying expands,
the facilities will increase to meet the demand.
And a couple of design niggles; it’s very easy for
the seat belts to sit over the top of your hip bones,
instead of behind them, and I would be inclined to
make that a specific pre-takeoff check for both occupants.
And finally, you can’t see the fuel level in flight.
It’s arguable that being able to see the level will tempt
pilots to stay up longer than otherwise, but I’d still
prefer to know my fuel state in the air. Stephen recommends a fuel flowmeter (an excellent idea), or if
you can’t afford one of those I’d be tempted to fit a
rear view mirror, as on older Mainair trikes.
Overall, this is a machine which should make
us sit up and think. The Aerochute isn’t a go-places
aeroplane. But how many of us, with our expensive
cross-country machines, have been frustrated by the
weather, however sophisticated they may be? Maybe
it’s time to evaluate what we want from our flying
and look at the alternative – drive to where you want
to go, then unpack your flying machine and enjoy
the scenery; make the most of the daylight and drive
home after dark. And at a price that won’t make
28
Microlight Flying
technical data
Aerochute Dual
Manufacturer
Aerochute International Pty Ltd, 12 Acheson Place, North
Coburg, Victoria, Victoria 3058, Australia. www.aerochute.com.
au. Proprietor: Stephen Conte.
Importer
Powerchute UK; tel 07929 320343; mob 07974 211850; wayne@
powerchute.co.uk; www.powerchute.co.uk. Proprietors: Wayne
Kimberlin and Richard Watkin.
Summary
Side-by-side two seat paraplane with brake control.
Rectangular wing with wingtip keels. Pilot suspended below
wing in trike unit, using brake toggles to control roll/yaw by
altering incidence of wing tips. Rectangular planform wing
with 15 closed cells of ripstop UV-protected nylon sail fabric
and four risers per cell. Undercarriage has three wheels in
tricycle formation; no suspension. No steering. Aluminium tube
construction trike unit without pod. Engine mounted below
wing, driving pusher propeller.
External dimensions and areas
Length overall 1.7m. Height overall 1.7m. Wing span 10.67m.
Constant chord, 3.2m. Dihedral N/A°. Nose angle 0°. Wing area
34.1m2. Aspect ratio 6.6/1. Wheel track 1.7m. Wheelbase 1.7m.
Mainwheel dia overall 0.35m. Nosewheel dia overall 0.35m.
Power plant
Rotax 503 engine, air-cooled. Max power 52hp at 6800rpm.
Ivoprop three-blade propeller, 1.473m dia x 10°. Gearbox
reduction, ratio 2.58/1. Max static thrust N/A. Power per unit
area 1.52hp/m2. Fuel capacity 30 litre.
Weights and loadings
Empty weight 107kg. Max take-off weight 300kg. Payload
193kg. Max wing loading 8.80kg/m2. Max power loading
5.77kg/hp. Load factors +4, -2 recommended, +6, -3 ultimate.
Performance*
Max level speed 40mph,. Never exceed speed 45mph.
Economic cruising speed 38mph. Stall speed 0mph. Max
climb rate at sea level 300ft/min*. Min sink rate 750ft/min at
38mph. Best glide ratio with power off 4.5/1 at 38mph. Take-off
distance to clear 15m obstacle 0m** on grass. Landing distance
to clear 15m obstacle 0m on grass. Service ceiling 10,000ft.
Range at average cruising speed 60-70 miles. Noise level dB(A)
LEL.
* Under the following test conditions:
Airfield altitude 0ft. Ground temperature 15°C. Ground
pressure 1013mB. Ground windspeed 0mph. Test payload
300kg.
Price including VAT
£13225
NA = Not available
Figures above are manufacturer’s/importer’s data
Figures in text are tester’s experience
February 2009
29