Flanders F3 (oz3029)

About this Plan

Flanders F3. Scale model pre-war monoplane, for CO2 power.

Quote: "I HAVE BEEN LOOKING for some time for another suitable design fo CO2 and eventually in Kenneth Munson's book Pioneer Aircraft found the FLANDERS F3. Flown at Brooklands in 1912 with a 60hp Green Engine, it achieved 65 mph and was only prevented from service with the Royal Flying Corps by the famous 'Ban on Monoplanes'. In fact, four were ordered, and should have been much better than the Biplanes put into production.

The machine was 12.6 meters span and 11.7 meters long with very simple construction, so this design was scaled up from Munson's drawings as accurately as possible bearing in mind the small scale drawings in the book. You can eliminate the detail and build it as a simple sport plane, or go into full detail, when it still (lies well enough to make your name and address very necessary.

Fuselage: Build two sides on top of each other in 2.5mm medium balsa, steaming the first 150mm of the longerons by sticking them down the spout of a kettle for 10 minutes Glue on the 0.4mm ply sides and the internal 0.8mm sheet doublers with their grain vertical. Join the two fuselage halves from the tail to the tank bulkhead and when dry complete, including the nose former. Cut out the cockpits, and glue on the top ply. Glue in the undercarriage basic 'U' and the bottom ply after cementing in the tank mounting.

Cement soft 2.5mm sheet over four sides of the nose and sand off to give a slightly rounded nose. Cut the slot for the tailplane. Now if you wish, cross brace the fuselage, on all four sides, back from the ply with black thread and edge the cockpits with insultation, split from wiring.

Tailplane: Cut from 0.8mm medium sheet to elevator line, then add elevators with the grain at right angles. Add 1.5 x 0.8mm ribs to top only. Weight down and leave to dry.

Rudder: 0.8mm sheet outline with 1.5 x 0.8mm ribs both sides.

Wings. Pack up the spars toallow for the undercamber of the ribs and assemble wing. Fit skeleton ribs and rigging blocks if required.

Covering: Use lightweight white tissue and make sure it has dried before water shrinking or it will pull away from the undercamber. Only cover the open section of the fuselage. Damp the tissue with water stained a faint brown with coffee for realistic ageing. Draw on the elevator hinge and the wing stitching with Indian ink (every 4th rib). Give fuselage ply four coats of banana oil, sanding down to a fine finish. Paint nose aluminium colour andfit dummy cowl slits from 1.5mm masking tape. Solder the axle to the first frame and the supports to the axle. Fit card fairings to first frame and both axles. Drill holes in fuselage and spring the supports into them.

Give the wings, rear fuselage, tailplane and rudder one coat of 50/50 dope and thinners followed by two coats 50/50 banana oil and thinners, pinning down between coats to give the wings 4.5mm washout. Don't try to give the aluminium a coat of anything!

Prop up each wingtip by 35mm and with sandpaper glued to a small block, sand in the dihedral, and the fuselage curve. Glue the wings to the fuselage, using a template, letting the first one set properly before you fit the second. Slot in the tailplane and glue in the tailskid and rudder. Fill in the tailskid with Clingfilm or equivalent.

Finish with a pilot, rigging post and rigging (I used shirring elastic), a dummy engine and condensers. Don't forget your name and address label! Bolt in the Telco engine, coil up any spare tubing and wedge in the tank.

Flying: Check the CG balance position is correct, give a gas charge only and launch into wind on a calm day. Correct up and down trim by bending the elevators. This is why you reversed the grain. Adjust the motor sidethrust for a right hand circle. On glide you will get a fairly vicious left hand turn if you don't do it this way. I assume it's the breeze, merrily whistling through that very large propeller. Without the Clingfilm in the tailskid it can turn into spin, though it flies fine without it under power.

I have built two and apart from having to glue a wing back on, they have suffered no damage and between them I estimate now they have put in 7 hours flying time! "

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