Winter Cup

In the years ahead, our model airfields will become increasingly rare, smaller, or disappear altogether. So what could be more natural than building smaller model aircraft as well? This was also demonstrated by the hand-launched glider competition held for the first time last year.

This new model aircraft class originated in France about 20 years ago and has since spread throughout Europe and the U.S. The basic idea was to finally eliminate the influence of thermals and downdrafts—only the model’s performance should determine victory or defeat. On the one hand, the power source was drastically reduced; on the other hand, flying was restricted to the (southern) winter months. Hence the name “Coupe d’Hiver,” meaning Winter Cup.

The New Year’s competition held twice in the 1950s by the MG Dübendorf demonstrated that model aircraft enthusiasts could be lured out of their warm hobby rooms even during this time of year.

Class CH — Coupe d'Hiver

Minimum weight: 80 g

Forged rubber: max. 10 g

Fuselage cross-sectional area: min. 20 cm^²

This rule has been abolished in some countries

Maximum flight time: 120 sec

1. The model is small and lightweight, so the risk of breakage is low despite its lightweight construction.
2. The model is easy to fly because the torque is low.
3. No major concerns about flying locations, even in the summer—after all, you don’t fly in strong winds.
4. Neither the construction nor the power system is expensive.
5. Short build time.

Wingspan: 900–1,100 mm
Wing depth: 100–120 mm
Wing area: 9–12 dm²
Elevator area: 2.5–3.5 dm²
Total area: 11–13 dm²
Fuselage length: 600–900 mm
Propeller: 2-blade, 370–420 mm diameter, 400–600 pitch.
Rubber: 6 strands, 6/1 mm; newer models even use 8 strands
. Total weight: approx. 80–100 g (new formula: 100 g).

The wings and elevator are constructed using standard spar-and-rib construction and covered with paper.

A 1 mm balsa tube with a diameter of approx. 25–30 mm is suitable for the fuselage. In some cases, stick-framed or box-type fuselages are still built. To achieve a fuselage cross-sectional area of around 20 ^cm², it is advantageous to use a large pylon. The difficulties involved in building a propeller are usually somewhat overestimated.

Climb to the right.
Glide. A wide left turn.
Engine runtime should not exceed
30 seconds.

The following construction plans for square fuselages are available from Aero-Modeller:

Baron Knight II, No. D 894
Nikolina, No. D 873
Deuzio, No. D 1048

Above all, however, the Austrian tubular-fuselage model “Nachtfalter” by Dipl.-Ing. Horst Wagner is highly recommended. These plans, which also include a detailed description of how to construct the propeller, were available from O. Schmolinske Verlag (Postcheck account Stuttgart 77788).

CH 71 by Johann Ployer is also a tubular-fuselage model; the construction plan was published in the magazine *Flug + Modell-Technik*, Issue 193, February 1972.

N.B.: E. Rohrer at Sonnenbergstr. 14, 8600 Dübendorf, Tel. (01) 85 09 02, will gladly provide construction plans and drawings, rubber, and know-how.

Which model flying club is organizing a CH and hand-launched glider competition next year?

Overview of the propellers as made by Erich Rohrer himself.