Longtime former editor of Flying Models
and Model Aviation magazines, and Model
Aviation’s current “CL Aerobatics” columnist,
Bob Hunt, holds his latest CL design that he
calls Second Wind. The airplane has twin
electric motors and retractable tricycle landing
gear. It was flown at the 2016 AMA Nats, held
in Muncie IN.
A terrific action photo of the Second Wind,
with Bob Hunt at the controls, shows the
landing gear retracted. Photo by Mike Schmitt.
Bill Stevens demonstrates how he attaches his
RC transmitter to his belt. His left hand operates
the throttle stick on the transmitter, while his
right hand holds the two-line control handle.
The Stevens AeroModel FatRat electric-powered CL model includes an RC system that
operates the motor throttle. A laser-cut parts
kit is available for this airplane.
RC Control Line
Q641: I found your February 2017 “Frequently Asked Questions” column, describing RC drag
racing, interesting. It seems that with
the advent of spread spectrum RC
technology, we are finding many new
applications for 2. 4 GHz RC systems.
I have heard that RC is being used
in conjunction with Control Line (CL)
flying. What is that all about? It sounds
A641: Because it involves CL flying, my
starting point was to contact my old boss
at Model Aviation, former editor Bob
Hunt. Throughout the years, Bob has
won first place in a number of national
and international CL Aerobatics (Stunt)
championships. He is one of the experts
in this aspect of model aviation.
To my surprise, Bob informed me
that both national and international CL
Stunt rules now allow for the use of RC
systems to supply control assistance. As
Bob pointed out, electric power works
best when using RC assist.
I’ve included a photo of Bob holding
one of his latest CL designs, which he
calls Second Wind. It has twin electric
motors and retractable landing gear. Bob
has also used other devices onboard that
alter the motor speed, depending on
the attitude of the airplane at any given
With electric power, you can vary
the motor speed from stopped, to full
speed ahead, and everything in between.
Electric retracts can also be operated
by the RC system. Until recently,
added controls required a third control
wire, which tended to add extra drag,
prompting a need for more power.
Bob’s Second Wind is a big airplane,
weighing 68 ounces with a 59-inch
wingspan. I’ve included an action photo
taken by Bob’s friend, Mike Schmitt, of
Bob flying his new twin-engine aircraft
with the landing gear retracted.
I wasn’t sure how many modelers
would build an airplane of that size,
so I contacted Bill Stevens at Stevens
AeroModel, to see if he was using RC
assist on any of his CL models. I also
reviewed Bill’s RingRat design, which
appeared several years ago in Model
Bill sent me several photos of the
RingRat variation known as the FatRat.
As shown in the accompanying photo,
the new version has an RC receiver
attached to the side of the fuselage,
near the wing’s trailing edge. A second
photo shows Bill making a flight with his
Note that his RC transmitter hangs
from his belt so that his left hand can
operate the controls. In this particular
case, Bill is using the transmitter’s
throttle stick to operate his electric
motor from high to low speeds and for
complete cutoff. You can’t do that with a
programmable timer or a fueled engine.
Because it is electric, the motor can
be restarted at any time after shutting
Years ago, I attempted to fly a CL
airplane and didn’t get beyond several
flights. I became sick each time I flew.
Because I couldn’t shut the motor down,
I became extremely sick. End of story.
There is also another possible
75 Model Aviation APRIL 2017 www.ModelAviation.com
FREQUENTLY ASKED QUESTIONS