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 Great Planes "Spitfire 40 Kit" - Review

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

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