The Birth of the FT/MC Old Racer

The weekend before last would dictate the death of my FT Old Speedster... which turned out to be a great thing!

I had ordered a smaller motor because the one I had was a bit on the heavy side for the Speedster. Built a new power pod, checked if everything was OK and off to the airfield I went.

No matter how much throttle I used, the plane would climb a meter or two, enter a spin and dive to the ground. It was obvious that the wind was to blame, but the lack of power seemed to me like the biggest culprit. After three tries and a broken prop, I decided to call it a day...

That night I gave the Speedster a pair of ailerons and installed the original power pod.

Unfortunately, the next day wasn't much different. As soon as I took off I realized that the ailerons were completely useless and the plane would still not climb. The only difference was that the plane would crash at a faster speed...

On my second attempt the plane behaved pretty much the same way until suddenly, much to my surprise, it started flying straight and level. That's when I noticed that one of the wings (the one facing the wind) was bent up 90 degrees! How was that thing even flying?

I went back home, trying to figure out what to do next, since I had no idea what the problem was...

Now I had two choices: I could either rebuild the mid section of the wing or make an entirely new one. I started by removing the wing and cutting the tips so I could reuse them but... I then decided to rebuild the plane my way!

I wanted a wing with similar looks but no polyhedral. I also wanted the plane to be able to fly as slow as the original. So I looked at my dust-collecting FT Spitfire, grabbed a piece of paper and made a template. The new wings turned out almost as wide as the original but, to make up for the extra weight, the wingspan is about 10cm longer. The dihedral is 9 degrees, almost as much as the Spitfire, simply because 10 degrees seemed too much and 8 degrees seemed too little. Unlike the Spitfire though, I placed the ailerons close to the fuselage instead of the wing tips so that the prop wash goes through them, otherwise I would have no aileron control at low speeds... at least that was my theory...

I know I could have calculated the area of the original wing and tried to make a similar one, but I was in no mood for math.

By the way... the wheel pants look great but... they just bring a whole new set of problems so... off with them!

Sooooo... here it is!

The finished product!

I opted for just one servo for the ailerons, since I'm not going to need flaperons on a slow flying plane. Anyway, I can always fit another servo in there if I need it.

Ailerons detail

As I was wrapping up I accidentally found the probable cause of my crashes: only half of the elevator was moving! With the plane on the ground everything looked normal but under load only the part attached to the servo moved. I reinforced the elevator with 2mm spring steel wire and some hot glue. It doesn't look pretty, but it works... You may also notice I tapered the fuselage where it meets the rudder. I don't think it gives much aerodynamic or weight advantage, but it just looks better.

The elevator reinforcement

So the plane was once again ready to fly (maybe) and it took me just one night to rebuild it. Would it fly? I would have to wait for the following Saturday to find out..

Saturday finally came and off I went to the airfield.

It flew! IT FLEW! It wasn't as slow as the original, but it wasn't that much faster either. I thought it would need some trimming because the aerofoil didn't end up exactly the same on both wings, but no. No trimming whatsoever. It just felt great! Easy to take off, easy to fly, easy to land! It can even handle a moderate wind with no problem! I got so confident that I even tried a loop for the first time... successfully!

I made an onboard video of the maiden flight using a Keychain Camera, but the viewing angle is so narrow that the footage is almost unusable... I'll see what I can do with it... It's a very good video if you want to throw up, though... :)

Anyway, here is a couple of post-flight pictures.

Since it became a whole different plane, it needed a new name. "Old Racer" was the first thing that popped up. The "FT/MC" part stands for "FliteTest / Miguel Coelho"... :)

Thanks to the guys at Flitetest and the help of Alfredo Morgado from the "Rodas no Ar" Club, in a couple of months I'm not only flying but also creating (successfully)! Can't thank them enough!

Have a safe crash,

Miguel