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SU - 47 (Sukhoi) 3D Aerobatics

jmrpb

New member
#1
Breaking the laws of Physics

Swept Forward Wings and 3D Aerobatic Flight
Swept forward wing


For some time I have this thought – Build and fly a swept forward wing rc plane.

Swept forward wings have incredible performance at slow speed with high AOA (angle of attack) capabilities and are also very good at transonic and supersonic speeds. The wind tunnel results have demonstrated that.

So, I’ve put my mind on it for some months ago and I’ve designed this aircraft which photos I also post. The photos were taken on a cold Autumn morning.

It has a simple way of vectorial thrust. It does almost any 3D manoeuvre that you can think of, with a very good vertical performance. And, of course, it is also very forgiven and stable if you want to. Most of the times, I catch it by hand.

The power system is the great secret for good low speed and high speed performance.

The specifications are:

Motor: Axi 2208/34 gold line;
Propeller: Graupner 9” 6” Slim cam (exactly 9” 6” - This is because the 9” 6” is perfect for acceleration from slow speed and high AoA and also have great behaviour at high speeds);
Batteries: #1 Lipo 3 / 850 mA/h with 30C (also by Graupner);
Speed controller: Jeti 8A (yes; just only 8 Amps, but this is more than sufficient. With this power system I can maximize my flight times – 10 minutes with 3D and Acro performance or plus 15 minutes with gentle use of the throttle stick (this is, if you can control yourself with this kind of machine :cool:).

The ailerons and the elevators are linked together by one carbon tube.

Roughly, the dimensions are:

Front to tail: 89 cm (overall length);
Front to leading hedge of the wing: 46 cm;
Wingspan: 66 cm;
Leading hedge swept angle (wing): 65º;
Wing trailing hedge swept angle: 55º;
The outer far part of the wing is: 13 cm (with ailerons);
Ailerons have: 8 cm;
Elevator swept angle is: 20º;
Dimensions of elevator (at widest point): 14,5 cm;
Dimensions of rudder (at widest point): 18 cm tall by 13 cm wide (at the bottom);
Weight: 320 grams or ~ 11 oz to ~ 12,5 oz range. Ready to fly (with this set up and battery).

The front part is made of yellow ‘polypropylene’ that makes it almost, and I say ALMOST, indestructible.

I hope that this brief description helps.

It has a simple form of KF airfoil (top and bottom exactly symmetrical for aerobatics).

It looks great in the air and it’s guaranteed that you’ll receive all the attention of other RC fellow pilots!

Follow your dreams and fly like there is no tomorrow!:D

José Bernardo
Lisbon, Portugal, Europe