"Tirteen only has about 15 pounds on the nose wheel in a typical, no
pilot, light fuel, fight ready confguration, so I always park with the
nose gear either partially or fully retracted. Tere is a small rubber
bumper on the nose that even acts as a parking brake when in what
I call 'grazing' position. I didn't use the Berkut hydraulic retraction
system and installed electric lif from the very beginning."
"Te Berkut canopy latches are a simple ball stud and cam slot design—
similar to what one would fnd when assembling anything from IKEA. A
canopy warning system activates voice warnings if takeof power is added
without the canopies fully latched. Canopy frames are all-carbon to
maximize stifness and have one main hinge in the center of the af bow.
Gas struts help raise/bufer the canopies and hold them open."
"I thought it would be easy to install a hole on the
underside of the forward strake for cabin air—
wrong! Not a molecule of air passed through my
frst vent attempt. It was August in Texas, so in
desperation, I duct-taped part of a Dr. Pepper can to
the side of the strake to make a scoop and soldiered
on with Phase 1 testing. Six versions later, I have
the scoop inlet I'm using today. It works very well
and even incorporates an 'air' drain. Without that
little hole, the air resonates in the plenum chamber
(like blowing over an open jug) and creates a loud
hum and vibration such that the eyeball vent spins
around like it's possessed."
"One of the most basic, and most important variables to
defne when making airframe aerodynamic changes is the
angle of attack at which the airframe and fxed fight surfaces
travel through the air…in this case, at max race speed. So
I came up with a cruise angle indicator. It's a repurposed
parking angle indicator for a camper trailer or RV. I tried a
smart level, but it was way too sensitive and jumped around
wildly. Te bubble in the arched glass tube is naturally
damped and is just as accurate. All of the fairings (elevator,
canard tips, winglet intersections, etc.) were installed using
the deck angles determined by this indicator.
"Te next aerodynamic mod I'm working on is trailing edge
fences to improve slow speed handling at high angles of
attack by inhibiting the spanwise airfow across the swept
main wings. Tis should also increase high-altitude speed
performance slightly as deck angle increases as the air
density decreases."
EAA Experimenter
17
