LET’S GO FLY A (POWERED) KITE

March comes in like a lion, and goes out like a lamb. What better way to play with that windy lion than to fly a kite? In my case, a “powered kite.” Who doesn’t like to watch a kite hover and dance on the wind? But no self-respecting RC pilot can leave a kite just a kite. It needs a motor and control surfaces! Every single time I fly it at the park, someone comes over to ask about that kite that acts like a plane or that plane that acts like a kite, and it leads to an introduction to Flite Test.

Made from a single sheet and a half of Dollar Tree foam board, the kite is designed for light weight, gentle handling, and high-alpha flight. Even in mild winds, it can throw out a kickstand and park in the sky, just like a kite. But it can also handle gusty winds without being blown into the next county. Relax the stick forward and it can also cavort in the sky like a homesick angel, doing graceful loops and flying inverted.

A Dollar Tree foam board is 30 by 20 inches. By angling the pattern from one corner, my kite is 33 by 22 inches, milking a little more lifting surface area from the sheet. The vertical stabilizer and rudder are about 7% of the wing area, as is the elevator. 

About 1-1/2 inches of polyhedral (the amount resulting from resting the wing center on a VCR tape box while the wingtips touch the benchtop) spaced about 1/3 across the wing adds stability, allows 3-channel control, and lends strength to the length of the plane.

Balance is a little quirky. The CG is 7 inches aft of the firewall. But because this is a low-wing design, the top-heavy weight isn’t stable when balancing on your fingertips. When the plane tips backwards slightly, the high weight tips it even further. Same when the plane tips forwards; the weight tips it further. I’ve found in the air the plane wants a little up-elevator trim to fly straight and level. Without that, the plane has a tendency to fly smoothly and then surprise you by diving suddenly towards the ground as if it was tail heavy. It’s not.

To save further weight, I cut the power pod in half, just behind the front tab. Cut it off square and a Velcro® strap will snug it to the wing nicely. Cut four small holes in the wing aligned with the landing gear skewers to loop rubber bands through the wing to hold the landing gear. 

The shortened power pod still has plenty room for the ESC and receiver, and even enough for the battery to tuck inside a bit, too. I fly 2S and 3S 1300 mAh batteries and get about 10 minutes of flight. I fly an 850 mAh 2S and get almost the same 10 minutes. The smaller batteries tuck deeper inside the power pod for balance.

Landing gear is the same wire used on the Swappable Series, but I use Ping-Pong balls as wheels. Heat a wire to melt holes for the axles. It’s truly landing gear, not take-off gear. I made the wire struts long enough to protect the propeller, but not so long as to pitch the plane in a take-off angle on the runway. I made the tail-dragger skeg extra long to protect the elevator during slow, high-alpha landings. A hand launch works just fine.

A piece of gift card glued where the landing gear meets the wing prevents the wire from denting the foam board on landings. 

If I had it to do over again, I’d move the servos as far forward as the pushrod wire would reach.

Add a crepe paper tail, and you have a powered kite.

“With tuppence for paper and strings
You can have your own set of wings.
With your feet on the ground you’re a bird in flight
With your fist holding tight
To the transmitter of your kite.”

(Apologies to Mary Poppins)