Spitfire IX plans are available from: Airborne Plans Service for AU$45.00 (2 sheets) plus P&H2 (AU$2.80
It is 62 years since the first prototype flight in March 1936 of the world famous Spitfire. This remarkable aeroplane is almost immediately associated with the Battle of Britain, making the Spitfire one of the most modelled aeroplanes ever built.
The design of this model is for the average modeller to be able to build a good sport scale Spitfire with a relatively simple structure. The construction of this Spitfire is no more difficult than a basic trainer model utilising flat tail surfaces from 9.5mm balsa, flat sheet balsa fuselage sides with rounded top and bottom and carved strip balsa ailerons. This model is designed as a semi-scale with the ability to be used a weekend flyer. The Spitfire fits easily in the average car and can be assembled in a few minutes.
I decided to build the wing in three parts due to the polyhedral shape of the wing, beginning with the centre section and then the outer panels.
Start by pinning down the spruce spars and then glue the ply and balsa ribs and dihedral brace together for the wing centre section. Glue the rear spar in place, then remove from the plan when it is dry.
Now using the same methods as previously, frame up both the outer wing panels over the plan. When completed, pack up the washout in the outer wing as specified and join to the centre-section at the correct dihedral. Add the leading and trailing edges now as well as the centre-section sheeting. While the panel was still on the building board, I sheeted and capstripped the wing to maintain the washout and avoid possible warps. The undercarriage blocks should be epoxied into place before the lower sheeting is added. After the sheeting is finished, a plywood plate is added to the lower trailing edge of the wing mounting bolts.
To simplify the strip aileron construction I tack glued them in place, after laminating sheet balsa, then carved them to shape on the wing.
Next mount your aileron servos where the plan indicates and then sheet around them. The wing tips can now be added and then carved into shape. Sand and finish the wing, adding the radiators and air scoop and then the wing is ready to cover. I used Koverall on the wing, tail surfaces and the fuselage.
Tailplane, Elevators, Fin and Rudder
The tailplane and rudder are built up from 9.5mm balsa which is straightforward and strong. First cut out all the relevant pieces, then build directly over the plan, making sure you cover the plan with glad wrap or waxed paper.
Sand and shape all these parts to the plan.
Be careful to keep all tail parts as light as possible to decrease the amount of nose weight needed to balance the model.
Begin by putting the fuselage doublers and the 3mm x 6.5mm stringers on the fuse sides making sure you have a left and right side.
Next glue F1, F2, F3and F4 to one side making sure they are all square.
Then glue the sides together and add the remainder of the fuselage formers.
After checking the alignment of the fuse, add the stringers to the front turtle deck then sheet with 3mm balsa. You may find it helpful to wet the balsa with ammonia and water to assist in shaping the wood easily.
Next I fitted the finished wing to the fuselage, then drilled the holes for the 6.5mm dowells to the front of the wing through the former for best accuracy.
Once the wing is mounted at the front, the alignment to the fuselage must be checked before adding the rear bolts.
When the wing is attached and true to the fuseleage, the tailplane and fin can be added.
Check the incidence of the tailplane and its alignment before gluing. The fin can now be added followed by the carved blocks.
Next add the rear turtle deck using tow sheets joined at the top. Bottom sheeting can now be added.
Mounting the engine was my next move, using a round piece of 3mm ply for the 2 degree offset sanded to wedge shape on the ply. I used a nylon radial mount in conjunction with my ever reliable O.S. 61 FSR. After fitting the motor the remainder of the cowl was carved from 12mm balsa blocks. Add the wing fairings now by laminating balsa together then attach the wing. Cover the area with glad wrap then glue the fillets on the fuselage with the wing in place. Sand and finish to prepare for covering.
After covering the entire model with Koverall, I primed the airframe with automotive acrylic primer surfacer to give good adhesion for the colour.
For the finishing coats I used enamel with a catalyst and a matting agent to give a scale-type finish. The finish I chose is based on 91 Squadron, Ludham, Norfolk in the spring of 1945.
I used a 200ml fuel tank and a J Tec pitts type muffler. Standard servos could be used safely through the entire model but I chose to use JR511 servos for all the flying surfaces. Dry weight was 3.8kgs with lead necessary to balance the model.
Balance can be achieved by judicial positioning of the radio gear, particularly the battery.
Unfortunately the grass on my flying field was very thick with clover and increased the tendency for the model to nose over when power was applied. Also a gentle crosswind caused the model with its narrow undercarriage track to weather vane. Once the model had some speed it tracked well and the take off was very smooth. Only minor trimming was necessary to gain straight and level flight. Next I gained some height and checked the model's reaction to the stall.
This was gentle and predictable and coupled with the elevator sensitivity showed the balance point to be accurate. At full power the model is quite fast and is capable of nice scale rolls, loops, immelman and stall turns. Knife edge attempts were poor due to the small rudder size and the amount of movement available. Good recovery was possible from spins and snap rolls but some speed is necessary because when the model slows down too much in aerobatics therefore it recovers slowly. This model looks best doing low flybys at 75% power, pity I didn't fit retracts. The landing was predictable and best with a fast shallow approach.
I was apprehensive about the typical Spitfire tip stalls but I had no problems with this model.
Overall this model flies very well and looks like a true warbird without the expense of a larger more complicated model. It is very easy to fly and once you are used to the take off tendencies it is an all round great flyer.
SPECIFICATIONS Spitfire IX
Type: R/C Sport/Scale Plane
Spitfire IX plans are available from:
Plan No. 666
Moulded Canopy: AU$27.00 plus AU$6.00 postage
This page was last modified on the 21-May-02