Le SZD 9 Bocian "1V"
The first time I saw this glider was a photo of a 1/3 scale model (so 6m). I was seduced by its slightly unusual rear canopy and its "retro but not too much" style, which made it a good candidate for a VTPR model in my eyes.
The idea ran through my head, I noticed via a 3-view plan and PredimRC that the stab volume was not far from reaching the 0.5 that I need on my aerobatic gliders. Then I noticed that it exists in a wood-kit, which would save me time. Finally... a little bit of time, because I was going to change:
- the stabilizer to make it bigger and full-flying
- the rudder foot to incorporate a stab travel mechanism at 2 x 90°
- the wing to give it an aerobatic airfoil (SC17 obviously!)
- the fuselage/wing junction since a new wing airfoil
Variants
There are several variants, named 1A, 1B, 1C etc. The best known are 1C (rounded wing tips) and 1E (straight wing tips). My model has some unusual and aerobatic-dedicated aspects, I name it "1V", with "V" for "Voltige" - and it has rounded tips.
The picture of a 1C model with a 6m wingspan that made me dream.
Distribution kit / personal work on a photo of 1C.
At the end of 2019, I therefore obtained the fuselage kit alone, then I started to model on the computer the modifications to be expected...
The wingspan of the stabilizer, originally 94cm, has been increased to 104cm to increase its volume. As shown in article 1, the rudder foot has been worked on to incorporate a 2x90° full-flying stab mechanism.
Each wing will be equipped with 1 aileron + 2 flaps to cover the entire span, and also with a differential incidence system (wingeron) hoping to achieve flat spins as with the Svolazzo.
Characteristics of my "1V"
| Wingspan | 4m50 - 177 in |
|---|---|
| Length | 2m - 80 in |
| Wing area | 117 dm² - 1550 in² |
| Weight | 7-8 Kg ? - 250-280 oz ? |
| Wing loading | 60-70 g/dm² ? - 19-23 oz/ft² ? |
| Wing airfoil | SC17 (14% - 8%) |
| Stabilizer airfoil | TP29 (9.3% - 6.8%) |
| 10 servos |
2 ailerons, 4 flaps, 2 wingeron, 1 stabilizer, 1 rudder |
The full size one
Here is what we learn on the Wikipedia page of this glider:
The SZD-9 Bocian (Polish: "Stork") is a multi-purpose two-seat sailplane that was designed and built in Poland at Szybowcowy Zakład Doświadczalny (Glider Experimental Works) in Bielsko-Biała, beginning in 1952. It was designed to be capable of fulfilling the needs of every area from training to competition flying.
Main designer was Marian Wasilewski, with Roman Zatwarnicki and Justyn Sandauer. The prototype SZD-9 flew for the first time on 10 March 1952, piloted by Adam Zientek. After flight testing was completed, suggested changes were incorporated into the design and production began, as SZD-9bis Bocian-1A (or simply "Bocian A"). The first production unit flew for the first time on 13 March 1953, and 11 units were built. Up to "1E" 1967 variant, more than 600 units were produced.
Apart from use in Poland, the type was exported to 27 countries, including Austria, Australia, Belgium, China, France, Greece, India, Norway, former East Germany and West Germany, Switzerland, Tunisia, Turkey, Venezuela, United Kingdom, and the Soviet Union.Polish pilots set many international records flying SZD-9s.