Sunday, 20 June 2010

The JART M70 is here!

I'll hand over to the man himself, Reed, to tell you about his new baby...

So this is how it goes: you hear that people want a rudder and flaps and a bigger version of the design and you say, "uh, ok!". To be honest I never needed all of that, I designed the plane as it was because it was all about me, me, me and I only wanted a simple plane that would fit in my car. Besides, I had to build them myself and didn't want to spend the extra time and money to fit flaps and rudder.

But here we are, 6 years later, and I find myself standing on a ridge, holding a 70" molded version of the plane with all of these bits and pieces wagging around, up down left right and all over. Just after launch I can already feel the size of the thing. Obviously I'm very familiar with the 56" wingspan, so having those big wings driving through the air is fascinating. At 72 ounces (yours should be lighter by 6 ounces or so) I'm surprised that the plane flies almost exactly like a 45 ounce standard-size JART, though I shouldn't have been. The extra size has a more than proportional affect on the airframe's efficiency so the numbers and the experience do match in this case.

For the first few minutes I flew with aileron and elevator only, just to get a feel for the handling characteristics. I certainly enjoyed it, and all of the maneuvers in the "teaser" video are with that setup. After a few minutes I decided to add flaps to the aileron movement and suddenly the plane felt more like a standard-size JART - very crisp and decisive in lateral control and overall very tight and neutral.

Then came the biggest surprise of all: the rudder. Honestly, I only added this to the design because a lot of people seemed to want it. For a 56" version I still wouldn't bother, but for this 70" version I thought the rudder might come in handy for inland "slermal" conditions where the pilot ranges out and looks for bubbles of lift away from the ridge and could use a flatter turn. It was a shock to me, though, when I pulled some rudder in on a racing turn and the plane came leaping out of the corner with unexpected energy. What I thought would be a fairly ineffective control surface is actually a very useful tool for keeping the nose straight through the turns and creating a "grippy" feeling, especially coming back from the downwind leg.

Landing this thing is just a breeze, especially if you already know how to land with flaps and/or crow. Once I got the elevator compensation figured out, those big flaps just bring the plane down to a crawl and you can land it on a dime in reasonable conditions. Being new to the flaps game it has taken me a few flights to get it dialed in, but I have a good technique now where I set the plane up behind the ridge and then pull in aileron reflex to kill some energy. Once the plane begins to settle down toward the LZ I pull the flaps in also and pilot the plane down to about waist-high where I pull the flaps out and let the plane sit right down. I missed a bunch of landings trying to learn this method and the poor plane took a lot of abuse dealing with my learning curve. But despite all of the bashing about, I never broke anything and was able to launch immediately every time - she's tough.

There will be many more flights and I'll post my impressions as we go. Can't wait to get her out to one of our DS spots to rev her up on the dark side!

Us too - thanks Reed! Here's a few detail shots in the meantime... check out that Kevlar joiner box!

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