Aerobatics has always been very
popular in France. Several competitions can be found in each year's calendar, including
both slope and aerotow flying. French manufacturers all carry one or more aerobatic planes
in their product range.
Airtech, one of the major sailplane
manufacturers in France, recently introduced the Psycho, which can be considered a smaller
brother of the Jedi, a 2.65 m glider that is very popular in our country. The Psycho has a
smaller wingspan, different airfoil (S6061) but the same general look. So, let's have a
look at this new kid on the block!
The Components
The whole kit is really good
quality. The wings (foam/veneer) are superb and have the flaperons pre-cut and articulated
under the skin with a special nylon ribbon. A balsa sub-spar is inserted in the foam core
before pre-sheeting to properly close the flaperon and the wing to improve the wing's
rigidity in torsion. Wing tips and leading edge are in place and pre-sanded.
The fuselage, which is available in
a choice of 7 different colours, has the snake outers already in place, the tail plane
crank in place with piano wire already connected, the wing alignment peg holes already
done and the fuselage joiner tube location marked. The carbon canopy is already cut to
shape and the all-moving tailplane supplied is the same quality as the wings.
Accessories such as the plywood
servo tray, 10 mm carbon joiner, pre-formed balsa block for the rudder and stickers are
also supplied, as are building instructions, in French...
Building
The time needed for the
construction is between 10 and 15 hours, which is short for a non-moulded plane. As usual,
I started with the fuselage.
Fuselage
What is noticeable on this kit is
that all the alignment holes or location marks are already done for you, that guarantees a
perfect final geometry of the plane and of course speeds up the assembly. Additional holes
are however necessary behind the joiner tube for the fixation hooks that keep the wings in
place with the aid of rubber bands, and for the servo connectors.
The servo tray is already cut-out
with holes for standard size servo. I fixed it in place with rapid epoxy and then added
fibreglass (110 g/dm2) which juts out on each side to improve the fastening. The joiner
tube is then placed in the fuselage with epoxy and micro-balloons.
The fin is closed with a balsa
fin-post and then reinforced with fibreglass from the rear.
The rudder is a pre-formed balsa
block, just needing a little sanding to prepare the surface and round off the angles
before covering.
A small piece of epoxy board
(printed circuit board) shaped and inserted in the rudder using rapid epoxy makes a simple
but efficient control horn. The rudder is then hinged using three plastic hinges and a
long piano wire provided in the kit.
Wings and Tail
Even though these wings are not
moulded only a little work remains to be done. This consists of enlarging the holes to
install the wing servos (Gr3341 in my case), extending the cut on the underside of the
ailerons with a mini-drill (3 mm) and making sure that the ailerons move freely.
The next step is to install the
alignment pegs (a piece of 3 mm piano wire) in the wing root with rapid epoxy and
installing a small hook to keep the wings in place just behind the wing joiner tube. The
aileron control horns are cut from epoxy board, partially inserted, then glued with rapid
epoxy.
The only thing to do on the
tailplane is to finish the root by sanding it to obtain a perfect fit with the fin
section. I then applied a little epoxy/micro balloon mix to the root to finish it properly
and cover any exposed foam.
Finally, a last quick sanding
before covering is needed, but it takes only a few minutes to do it, including the final
cleaning with the vacuum cleaner, followed by a stroke of the hand, which is an amazing
tool for evaluating the results!
Covering
Airtech provide, at a reasonable
price (or as an option with the kit: 2 colours, one for the underside, the other for the
upper side), a covering material that I have used for several years and that I strongly
recommend to everybody www.oracal.com
It's a vinyl adhesive tape (50 cm
wide) and the exact colour of the fuselage. The advantages of this covering material are
numerous. It is very quick to use, less than 1 hour for the two wings, it's very strong,
long-lasting and the weight is reasonable.
I'm such an enthusiast that for 5
years now I have not used any other covering materials! Kevin asked me to prepare a
technical article about this subject. So stay tuned! (Strong, cheap, long-lasting, easy
and quick to use - all words I love to hear. KN)
I also used vinyl adhesive tape for
the decoration. I wanted an extremely flashy colour scheme but easy to cut (I use a Roland
cutting machine interfaced with CorelDraw software).
The difficulty is to assemble the
different colours correctly on the support paper before transferring all the decorations
to the wing. I think the result is good, isn't it?
Radio Installation
As I said before, I choose Gr3341
(Graupner www.graupner.com ) because
they have been designed especially to be mounted horizontally in the wings. They are
screwed onto small wooden blocks and are easily removable.
Wing servo connectors are the
Multiplex grey type with the connections potted in hot glue after being soldered. The hot
glue does a great job of protecting the wires and can be removed very easily with a cutter
if something happens or if you want to re-use the connectors. Hot glue is also perfect
because there is no chemical reaction with the wire insulation as can happen with silicon
for example.
The aileron pushrods are made with
3 mm threaded steel, aluminium tubes and metal clevises.
In the fuselage the installation is
very straightforward with the servos in tandem, a 4 x 1800 mAh battery in the nose and the
receiver between them. I used a Graupner C19, 9 channel receiver and Multiplex Europa BB
servos for the elevator and the rudder. You can use any of the standard servos available
on the market since space is absolutely not a problem (that's a real change from the
F3B/F3F moulded planes I usually build!).
Step On To The Scales!
It was a bad surprise to discover
that I needed more than 200 grams of lead in the nose to obtain the correct CG of 90 mm
from the leading edge, just behind the wing joiner. However, my fuselage is pretty heavy
(but very strong) which explains this extra lead in the nose. The total weight is 2 kg so
the wing loading is around 50 g/dm2. This is a little bit high for the glider size.
I gave my feedback to the
manufacturer who has now modified the fibreglass layout of the fuselage to save around 75
g, mainly on the rear part. A new servo layout has been also adopted. These modifications
are now on all Psychos produced.
Flying
I had the chance to fly the Psycho
in all types of conditions during the spring season in the Alps. To give you an idea of my
background in aerobatics I've previously enjoyed such models as the Axel, Jedi, 2.8 m
Roedelmodell Fox and the Voltij.
In light conditions the Psycho is
pleasant. The use of the flaps gives more lift and the dihedral greatly facilitates
thermal turns, but the sink rate (due to the wing loading of around 50 g/dm2) means it
doesn't compete with lighter planes. You have to compensate with a better flight strategy.
However, note that with the
modification that the manufacturer has now applied to the fuselage moulding, performances
should be much more interesting. I recently met a Psycho owner who has a lighter version
(at 40 g/dm2) and he told me that he was very pleased with the thermal capabilities of his
plane.
Anyway, the Psycho becomes really
interesting when the wind blows a little bit more and then you can start to think about
doing aerobatics.
Words that characterise the Psycho
are, smooth, inertia and stability. This is THE plane for 'academic' aerobatics, meaning
it will execute all the figures as they are described in the school manual!
The plane is very responsive and
consistent on all axes, without being too nervous. Rolls and 4-point rolls are very easy,
even if the roll rate is not demonic. High speed flicks and spins are nice too. Because of
its inertia vertical manoeuvres are a piece of cake. Loops, inside and out, vertical
eights, cuban eights etc. present no problems.
I like very much to chain several
(up to 10!) stall turns together along the edge of the slope, then to finish with an
inverted exit and a half roll. The Psycho is just perfect for such exercises!
Once again, the dihedral, which
could appear as an enemy, is in fact an ally! It doesn't affect the horizontal manoeuvres
and allows the intended trajectory to be maintained.
The Psycho also shows very good
behaviour during inverted flight considering its non-symmetrical section. The compensation
(down of course!) is minor and the speed stays reasonable. I have already flown more than
30 minutes of inverted flight without any problem.
The only concern I have is about
the knife-edge flight. The side area is good but not sufficient and not well balanced
between the nose (too short) and rear part of the fuselage to correctly maintain the plane
in this position.
Landing with flaperons up increases
the sink rate but does not decrease the horizontal speed much. To slow the Psycho down
(sounds like a line from a cheesy horror movie! KN), it's necessary to add some
compensation to raise the nose. Don't hesitate to do several attempts if you are landing
in a small area.
I prefer to repeat the approach and
land the plane safely than landing the first time but damaging the plane.
To finish the flight test I had the
opportunity to lend the plane to some friends of mine during a flying session; they
refused to give it back to me so I consider that they enjoyed the plane!
Conclusion
To summarise, I would say that the
Psycho is really a good aerobatic glider that I definitively recommend to beginners up to
intermediate level pilots. The kit quality is top level, and you won't have any headaches
during the construction, which is well thought out with absolutely no bad surprises, a
point that I always appreciate on a kit.
And for the others who are looking
for thrills? Well, the Psycho is maybe too well behaved. Anyway, this compact glider
remains excellent value for the money.
Specifications
Wingspan
2. 30 m
Wing section SD 6061
Wing area 40 dm2
Weight 1900 g
(tested 2000 g)
Wing loading: 47.5 g/dm2 (tested 50 g/dm2)
Price
1590 Francs (around £150 or $215)
Available from Airtech, 235 bis
avenue de Grenoble, 38 180 Seyssins, France. Phone number: 33 4 76 84 07 54.
Website: www.airtech-rc.com
Email: airtech@airtech-rc.com
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