GreatPlanes
- Spitfire 40 Kit
– Review by Kerry Smith
As with a lot of people, I’ve been in love with the Spitfire as far back
as I can remember, so when I got into aero modeling, I knew that I would
eventually build a Spitfire. I was in Dallas, Texas on business, and saw
the GreatPlanes Spitfire 40 kit in a model shop. I couldn’t resist and
walked out of the shop with the kit, retracts, 3 rolls of MonoKote covering
and all the other bits and pieces that the box said I would need to build
this plane.
To say that this kit is well packed and protected does not do it justice.
It made the trip home from Dallas as a piece of checked baggage and arrived
with no damage at all to the kit. The box wasn’t as lucky!
Tail Feathers
You start this plane by building the tail first. The stabilizer and
the elevator are built as one piece by laminating 1/16” balsa strips on
the plan and then separated later. This enables you to achieve the characteristic
curves of the tail and keep the tail weight low (a good thing in a war
bird) without great effort. Building and finishing the stabilizer ready
for covering only takes an evening.
Next comes the fin and rudder. This is where you encounter one of the
shortcomings of this kit. The shape of the fin is not quite correct, as
it does not have the characteristic filleted shape, fore, where it meets
the fuselage.
I decided that this needed to be corrected and found, as I had studied
the building instructions in their entirety before I started building,
that the problem could be resolved later on when the fin is attached to
the fuselage. I finished the fin and rudder ready for covering, once again
this part of the construction only took a night.
Wing
The next part is the wing. This is the point where you need to decide
between fixed landing gear and retracts. I chose to use mechanical retracts
and had no problems at all.
The wing goes together very easily but is also the area that requires
the most care. You need to build straight and true. Don’t rush it even
when it is tempting with a wing like this.
The ribs all have jig tabs that are a bit fragile but make it easy
to build a wing that is straight and has the required washout. Follow the
11 pages of instructions on constructing the wing to the letter even when
you cannot see why. It works out in the end.
Fuselage
This is simple and goes together easily except for two areas. At two
points you are required to bend 1/8” balsa sheeting around the fuselage.
This is the only place where the choice of wood was not good. Even with
a lot of water, ammonia, care and patience, the wood broke. This is not
too serious but it detracts from an otherwise excellent wood selection.
The second area is the fact that GreatPlanes has chosen to omit one
of the most distinguishing features of the Spitfire, the wing fillets.
These were simple enough to add but would have been better if they were
included in the kit and the plan.
Power Plant
Next step is to mount the engine and fit the cowl. This is another
are area of disappointment if you choose to power the plane with a 2-stroke.
(I chose to use a Thunder Tiger Pro 46.) If you fit a 4-stroke engine it’s
not an issue. The instructions say that the muffler used in the prototype
was a Slimline muffler, which, in my opinion, is not adequate.
I chose to make my own muffler that fitted between the engine mount
and the firewall. It was a huge task but paid off as no part of the engine
or muffler protrudes from the cowl other than the outlet pipe for the muffler.
There is also very little information on the cooling holes in the cowl.
Even the pictures don’t give you much of a clue but sticking to the rule
of thumb that says: “you need twice as big a hole for the outlet as you
have for the inlet”, works.
Covering Finishing
 |
Covering the tail is quite simple but the wing is quite a bit more complex
and the fuselage, particularly around the wing fillets, is difficult. |
Take
your time and if it doesn’t look right, do it over. I covered mine in Olive
Drag and Tan MonoKote on top and Dove Grey MonoKote underneath.
The decals that are provided are of good quality and go on easily but
I chose to test fly first before I detailed the plane.
Radio Gear and Balancing
The radio gear goes in easily if you follow the instructions. The model
balanced after placing some lead in the rear of the cockpit. This is probably
because the muffler turned out quite a bit heavier than expected. Even
with this, the finished weight was only 1.8kg, quite a bit under the 5
– 6 lbs noted by the manufacturer.
Flying
 |
I took a number of people’s advice and test flew the model before I
did the finishing details. This turned out to be an unnecessary precaution
but I would still recommend it. Before I flew the plane, I spent about
30 minutes taxiing the plane to get used to the ground handling. This is
important so that you can be confident while taking-off for the first flight. |
On the first outing, I couldn’t have asked for better weather and took
off down the field towards the dam. I advanced the throttle slowly (something
I’ve not been able to get myself to do as well since then) and the tail
lifted off the ground first with the whole plane climbing, without any
up elevator being applied, a short distance later.
I made the plane climb out and then turned gently to the right on the
lookout for signs of any problems. There were none!
I did a few circuits with Grant Furzer telling/urging me not to fly
at full throttle. I wasn’t. In fact I was flying at a little over half
throttle. This is one quick plane!
After a while, I gained some height and slowed it down as much as I
could to check for any nasty behavior. It just dropped the nose and showed
no inclination to drop a wing. I then throttled up, came around and lined
up for landing. |
 |
 |
I brought it back to idle and the plane sank slowly to the ground.
It touched down and ran down the field with the tail wheel up until I applied
a bit of up elevator and forced the tail wheel onto the ground. The landing
gained the approval of everyone watching.
I fueled it up, drank a cup of coffee and waited for my hands and knees
to stop shaking. The second takeoff was just as uneventful but maybe not
as slick as I increased the power too quickly. Once I had height and had
done a few circuits, I decided to test the reaction when I retracted the
landing gear. When I flicked the switch, the gear retracted and the nose
lifted a bit. This was not unexpected and is not a problem. |
This very fast plane became even faster and looked great coming down
the field at about 20ft. After “hooning” around for a few minutes, I lined
it up for landing and all was great until, about 2 feet after touchdown,
the wheel twisted and broke one of the retracts out. I had forgotten to
file a flat onto the retract to prevent this. This was the end of flying
for the day but was a simple problem to resolve and took less than an hour.
All this and subsequent flying has been done with control throws set
up as per the instructions and on high rates. This plane is very stable
and, with care, does not require half rates.
This is an excellent kit that I would recommend without hesitation.
The negative points are minor and once overcome make for a very enjoyable
plane. |
 |
 |
Manufacturers Specifications:
Wing Span - 54.75 in (1390mm)
Wing Area - 526 sq in
Weight - 5 - 6 lbs
Wing Loading - 22 - 26 oz/sq ft
Fuse Length - 48 in (1219mm)
As Built:
Engine – Thunder Tiger Pro 46
Retracts – Hobbyco mechanical retracts
Muffler – Custom design
Finished weight – 1.8kg
Update
I have subsequently moved the lead that I needed to obtain the correct
c.g. all the way back to the tail. This has helped, but did not cure, the
full-scale like tendency to nose-over. This plane has proven to be a reliable
fun plane and a great entry into scale models.
Kerry Smith
|
|