Blackhorse Sukhoi ARTF

Another moment of weakness that seemed like a good idea at the time. At Sandown in May 2003 I bought an ARTF Blackhorse SU-31, as I wasn't getting time to build and the Mystic was not convenient.

It was 'cheap' looked good, seemed well built and went together well. However it flew like A PIG!! I think it was like the Eurofighter - intrinsically unstable. Unfortunately my poor brain doesn't have the computing power to compensate for an unstable aircraft!

After a few brown trouser flights and some damage I was all set to bin it, when I decided to take a good hard look at the wing. I found one tip section as you'd expect i.e.. simple symmetric not too deep. The other tip section looked like a banana, the underside was concave. No wonder it was prone to unpredictable flicks and tip stalls.

Funnily enough there was to be quite a lot of stuff on the web about problems with this particular model, but I didn't find that until after I had bought it.

A further inspection of the wing, having cut it in half, showed a poor internal build standard as well. Looked good on the outside but too many interspar webs where poorly fitted

 I decided to built a new wing for the model, as the fuselage was still sound. I drew up a simple foam wing for the job, using the same wing section (the good one!) as the original. I did straighten the leading edge to make life easier, but other wise it was a simple copy of the planform of the ARTF wing.

I sent the drawings off to be made. I have made my own foam wings before, but remember at this stage of my life I didn't have a lot of spare time. Unfortunately when the wings came back the guy had made them with a swept back leading edge, instead of a swept forward trailing edge. Oh joy!!! However on inspection I found that I hadn't specified the TE on the drawings. OK  he should have asked as well, so it was 50:50 in the balme stakes - so I put that down to experience, and got on with it. A quick bit of building of a new centre section and hacking the inboard end off the wing panels and I had a good wing again.

If anybody wants the plans for this wing you can down load them in dxf format by clicking right.

The new wing  solved the flying problems. It not longer flicked at unpredictable times, or in unpredictable directions. Also I know that the wing is sound.

wing plans dxf

I must say that this experience has put me off ARTFs. I guess the moral of the story is two fold.

1) Research a model before you buy -don't impulse buy because it looks good or is cheap and

2) You probably get what you pay for - there are many ARTFs out there, they can't all be bad.

The model currently resides in my attic - it will probably remain up there until either we move or I get fed up with looking at it. In either case it will likely be dumped. I have lost count of the number of time I have put an old model in the attic with the view " I may fly that again some day" only to dump it years later.