The Flying Rainbow

From the first time I turned the pages of the coveted "On the Wing" book, by Bill and Bunny Kuhlmann, (which I borrowed from Richard Tapp before I got my own, (Thanks again Richard)) I wondered what the Flying Rainbow Wing design of the late Dr Walter Panknin looked like.

Walter is in a white shirt with his left arm on his nephew, Rob Klopp. The others are from RC-Gummersbach, the flying club in Gummersbach, Germany.

Thanks to some information from Lee Murray, I finally found out.
Lee supplied me with the details and now you all can know:-

The chords are as follows:

Root E222 15.75 inches (400 mm)
Mid E226 13.4 inches (340 mm)
Tip E230 11.0 inches (280 mm)

Linear taper used

Total span 126 inches (3.2 M)
Foam cores transition between the three airfoils so that the mid point spanwise from root to tip is the mid airfoil.
CG 2.25" (57 mm) from root of TE.
There are fins added for visibility which have a root chord of about 270 mm, height of 300 mm and tip chord of 130 mm with a vertical trailing edge.
Elevons are 700 mm long and are located within 60 mm of the tip. The depth of the elevons are 65 mm.

designed by: Walter Panknin

Technical Data:


Wingspan 3.20 meters
Wing Area 109 dm^2
Wing Loading 33 g/dm^2
Winglet Area 2 * 6 dm^2


Wingspan 126 Inches
Wing Area 1690 sq in
Wing Loading 10.8 oz/in^2
Winglet Area 2 * 93 in^2

General Dimensions
Aspect Ratio 9.4
Sweep Angle t/4 19.6 deg
Geometric Twist -2.5 deg
Profiles E222, E226, E230

Notations on Elevons Movement:
+36 mm Aileron + Elevator + (Two Movements Together)
+20 mm Aileron + (Only Aileron)
0 mm
-12 mm Aileron - (Only Aleron)
-17 mm Aileron - Elevator - (Two Movements Together)

Key parts for experienced builders are available from
Lee Murray

E-mail Andy MacDonald