Well, I am making my first R/C aircraft, and doing it from scratch. Dont worry, I know I am throwing myself in at the deep end, with punctures in my water wings. But feel good, since BMatthews talked me down from making a scale Hawker Typhoon for my first model!

But anyway, the situation is I am making an aircraft to go around my 50 year old 3.46cc throttleless engine. It is supposed to be an advanced trainer, with neutral stability, capable of slow speed but high torque aerobatics. I figured this forum was the best place for my remaining queries on its design.

I will note down the current details of the design, and then point out the things that dont seem to go too well at the moment.

Power Plant:
Volume: 3.46cc (0.21 cubic inches)
Offset: 2 degrees down & 1 right.

Wing:
Area: 3125cm sq (484.3 inch sq)
Span: 125cm (49.2 inch)
Chord: 25cm (9.8 inch)
Aspect Ratio: 1:5
Taper Ratio: 0
Dihedral: 2 degrees.

Airfoil:
Type: Semi-symmetrical
CG location: 30%
Point of Max Depth: 30% (2.5cm above, 1.5cm below reference line (1 & 0.6 inch)
Angle of Incidence: 0 degrees.

Ailerons:
Area: 10% wing area
Dimensions: 50X3cm (19.7X1.2 inch)

Stabiliser:
Area: 25% wing area (including elevators)
Elevator Area: 30% stab.

Fin:
Area: 14% wing area (inc rudder)
Rudder Area: 50% fin

Fuselage:
Total length: 94cm (37 inch)
Nose-Leading Edge: 25cm (9.8 inch)
Trailing Edge-Tail: 44cm (17.3)

Landing Gear:
Front Position: Axle 18cm (7.1 inch) below leading edge.
Front Diameter: 7cm (2.8 inch)
Width: 31.25cm (12.3 inch)
Tail Wheel Position: 5cm (2 inch) fore of tail, & 5cm below reference line.
Tail Wheel Diameter: 4cm (1.6 inch)

Target weight:
1.2kg

My query is the stabilisers and the fin. I have made a rough sketch in autocad of the dimensions fo the key features of the aircraft, and I cant help but think the fin deffinately and the stab probably look a lot larger than is the norm for other models of this type. THe DWG file is [link=http://h1.ripway.com/greenskintau/finissues.dwg]here[/link], can anyone tell me if they think the proportions are right/wrong/how to ammend them?

I dont mind the current layut of the stab so much, but I cant help thinking the fin looks like a joke...Any help is greatly appreciated. My thanks to BMatthews for helping me this far.