Powering the Kaos for the glow portion of the review was this O. S. 65AX
two-stroke. It can be mounted vertically or on its side as shown here.
The die-cut parts of the motor mount box are the only parts that
require glue. When finished, it bolts into the same mounting holes and
uses the same hardware as the glow engine does.
The tail assembly is
held in place with
these two locknuts to
make assembly and
A plastic wrench is
for this purpose.
Photos by the author
the proper balance without extra nose or tail weight.
The completed electric version weighed 6. 4 pounds, and
8. 125 pounds with the battery.
After the flights were made with the electric-powered
Kaos, it was back to the shop to change it to glow power.
Because everything bolts into place, it was simple to
remove the electric motor box from the firewall. With
some measuring and drilling, the O.S. 65AX engine was
mounted to the two-piece motor mount halves. The
mount was then bolted to the firewall using the same
bolt pattern and screws that held the electric mounting
box in place. Nice!
By the way, the engine can be mounted either upright
or sideways. I chose the side mount to blow most of the
glow fuel’s exhaust underneath the airplane.
A throttle servo needed to be installed, along with
the throttle pushrod, then the tank. The tank’s internal
plumbing was another step completed at the factory. It
comes set up for a three-line system. After slipping the
tank into place, it’s restrained using the same hook-and-loop material that secured the LiPo batteries. All that’s
left is to measure, cut, and attach the included silicone
tubing in the proper places.
A template is included in the manual to trim the cowl.
It’s not the right size, but that’s by design. It is actually
smaller so you can get the general placement, then
slowly work at enlarging the hole, cutting as needed until
all of the clearances and holes are in the proper position.
With the glow conversion completed, the Kaos
weighed in at 7. 75 pounds dry. This still fell into the
recommended CG range, so it was good to go.
Because of the timing of this review, I didn’t have the
luxury of waiting for a nice, sunny day for the maiden
flight with the electric power system. It was windy— 15
mph with a lot of gusts—but it was off to the field to
see what would happen.
My field has some grass in the pit area. It’s mowed
quite short, but it’s still rough. The electric system
easily pulled the Kaos through the grass and up to the
runway. Lined up into the wind, I put on the power and
the Kaos rapidly accelerated and was able to lift off in
approximately 100 feet. Climbing up to a safe altitude
took merely a few seconds and it only took one pass to
trim the Kaos for level flight.
Bringing the Kaos in for the required photo passes, you
can use whatever age-old catch phrases you’d like: it flew
as if on rails, it grooves like a Pattern aircraft, or it flies like
a dream. They’re all true. Even in the gusty winds, there
was no problem placing the Kaos exactly where I wanted.
After the photos were complete, I took it up a bit to see if it
flew the way I remember my original Kaos flying, and it does.
The RimFire and 6S LiPo provide more than enough power to
take the Kaos vertical and keep going until you decide to bring
it back down to earth.
Because of the ample power, aerobatics are a breeze. Make
the loops, Cuban 8s, etc. as small or as large as you want, even
in the wind. It takes a bit of elevator to hold inverted flight
and it doesn’t do knife-edge maneuvers or perform crisp point
rolls, but the Kaos was never meant to do that.
67 Model Aviation JANUARY 2016 www.ModelAviation.com