Bob Holman's Airborn 600
Many historic models are aesthetically pleasing in design and in flight, and one of my favorites is the Airborn. I wanted to modify this free flight design for RC and electric power, and build a scaled-down version that would meet the two-pound weight limit of the Park Pilot Program. To build the basic model, I got the plans, laser-cut bulkheads and wing ribs from Bob Holman Plans (bhplans.com).
Bob Holman parts and plans are of exceptionally high quality, which makes building the Airborn 600 a dream. The completed model weighs roughly 21 ounces with a 2300mAh battery. With a 68-inch wingspan at 600 square inches of area, it’s a delightful slow flyer.
On takeoff, I move the stick to approximately 1/4-throttle to let the air start blowing over the tail, then, with the model rolling steadily forward, I gradually advance to 3/4 and commit. The Airborn’s efficient airfoil and light wing let it lift off the ground with ease. Full throw on the control surfaces gives the airplane authority in the air. Anywhere from 1/4 to 1/2 is fine for flying around in a straight-and-level attitude, or executing graceful, moderately banked turns.
Landing the Airborn 600 is easy. Just line it up with the landing area, cut the throttle on final and let the airplane glide in on a moderate downward glide slope. Adding slight flare as it nears the ground never fails to impress any spectators.
Building and flying this model has been a joy, and incorporating the RC and electric-power technology was a new experience for me with a classic old-timer design. A lot of thinking and advance planning went into to addressing the RC and EP modifications in comparison with how this model was originally intended. In the end, it proved to be a fun and overall rewarding experience, and I hope you find it so as well.
With a 68-inch wingspan at 600 square inches of area, it’s a delightful slow flyer.
The Airborn 600 in flight.
Hitec HS-81 servos, a Futaba R617FS receiver and a 2300mAh LiPo pack are on the radio tray.
Read the entire construction article on pages 26-27 in the Fall 2013 issue of Park Pilot. Order Bob Holman's Airbron 600 plans at www.bhplans.com.