Duo-Mono (oz7945)

About this Plan

Duo-Mono. Control line semi-scale model of the Delanne Sport Model 20.

Quote: "Is it a tailless bipe or a mono with a misplaced empennage? The Delanne builds easy, performs like a dream.

Experiments in various wing arrangements with full-scale aircraft have resulted in some pretty strange shapes through the years of aviation development. Successful results have been frequent; yet fallen along the wayside we find combinations such as the canard, tandem wing and circular wings. Today designers have pretty well settled for the conventional wing stabilizer or all wing set-up.

The original versions of Maurice Delanne's double-mono-plane were singularly successful. They possessed a high degree of maneuverability, a high top speed, together with a very low landing speed. Air Trails has been fortunate in securing from Mr. Delanne drawings of his Sport Model 20 which was built and flown in France during 1938-1939.

The design lends itself admirably to sport control line flying, and although not a strictly scale version of the large Delanne 20, we hope the design liberties taken will not offend.

The 31 inch span model weighs in at 24 ounces. Considering both wings as effective area (according to Mr. Delanne) gives a total of 280 sq in wing area. Wing loading is 8.5 oz per 100 sq in. If only the front wing is considered effective area (184 sq wing loading comes to 13 oz per 100 sq in. The model has good stability in flight, but we would rather assume the loading to be higher than the 8.5 oz figure. If you split the difference, loading is probably closer to 10-11 oz per 100; at least that's the way the model feels out on the end of the wires. So don't attempt the full stunt pattern with this ship although you can have plenty of fun with big loops, horizontal eights and inverted flight. The K&B 29 in the nose furnishes plenty of power - speed is a little above 70 mph.

Construction follows standard practices and a strong light structure has been achieved without excess weight. The fuselage can be built first. Cut out the two 1/8 sheet sides. These should be of medium hard or hard stock..."

Direct submission to Outerzone.

Quote: "Steve, I came across a great line control plane from the October 1950 Air Trails magazine, the Duo-Mono. I have no way to clean this plan up or put it into CAD [ed: fixed - is now scaled and cleaned]. From a cursory internet search, this type of aircraft has almost been mostly forgotten. I see someone submitted a more basic model than this. Hopefully the readers will appreciate this little known gem. Marc"

Supplementary file notes

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