AOPA Pilot Magazine - July 2016 - 56

How do you make a Cub go fast?
CubCrafters' Pat Horgan explains.

THE XCUB retains the Super Cub's

legendary short-field capability and
operates on grass strips with ease.

TESTING THE XCUB

vertically and rolling over rocks the size of
bowling balls. CubCrafters takes a different approach with its XCub.
Instead of incremental reductions to
an already slow stall speed, CubCrafters
transforms this backcountry aircraft by giving it a fast cruise speed and long range.
At 120 mph true airspeed, for example, an
XCub pilot can cut fuel burn to 6 gph or
less and have about eight hours of endurance. At the same time, the XCub retains
the Super Cub's defining slow-flight and
short-field capabilities. With flaps down
and moderate braking, its landing roll is
just 173 feet, and its takeoff roll is 282 feet.
Another defining characteristic of the
Super Cub is poor control harmony, a trait
pilots have always accepted as part of the airplane's personality. A certain amount of slop
is unavoidable with pulley-actuated ailerons,
and pilots have always just dealt with that
friction, adverse yaw, and other quirks. Not
anymore. The XCub's ailerons are controlled
via push rods for a tight, precise feel.
Outside Yakima's airspace, I go through
some get-acquainted maneuvers. Lazy 8s

continued from p. 55

Jacob Varhaus, a diligent young CubCrafters engineer, would stay on the ground to monitor the flight
online (via flightradar24.com), radio, and SPOT tracker.
Perhaps wanting to lighten the seriousness of the
moment, one of the other members of the flight test
team told Varhaus to add a final item to the checklist.
"Make sure to brew a fresh pot of coffee before we get
back. It's going to get cold up there."
Pegasus Airpark near Phoenix is a private residential
strip behind two sets of locked gates. It provided an outof-way, good-weather location for this series of XCub
flight tests. The team tried not to draw attention to what
it was doing, and kept their hangar's folding door closed
whenever airplanes weren't coming in or out.
They had been working every day for three weeks to
finish the 400-plus required spins and 1,500 test points,
and they had put more than 200 flight hours on the two
XCubs being tested. One Cub had traditional bungee
landing gear, and the other more streamlined Grove
spring gear-and data had to be gathered for both.
High-altitude takeoff and landing performance was
measured and verified at Show Low Regional Airport
(elevation 6,415 feet), and now the spin tests were
about to take place over a remote area about 15 miles
from the Casa Grande VOR.
In the cluttered hangar, Varhaus listened on the
radio and watched his computer screen as two blips
56 | AOPA PILOT July 2016

reveal a finely balanced pitch and roll feel.
The airplane is energetic in climb, and its
relatively sleek lines allow it to accelerate briskly downhill. Steep turns require
an absurdly small amount of airspace, and
the expansive view makes maneuvering
through this scenery joyful.
Slowing down for a stall series, the
chirping aural stall warning comes on at
about 50 mph. But with just one person
aboard, half fuel, and idle power, I don't get
a stall break. The airplane just descends in
a nose-high attitude with the wings level. I
add a few inches of manifold pressure, and
that increases the pitch attitude and angle of
attack enough to get a crisp stall break with
slight left-wing drop. Recovery is immediate
with relaxation of back-pressure.
Adding flaps via the manual lever at 80
mph (the top of the white arc) produces
a noticeable pitch up. The pitch change is
much less pronounced at slower speeds,
and experienced CubCrafters pilots recommend 70 mph or less for flap deployment.
Flaps-down behavior is unremarkable, but don't ask me the speed at which a

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Table of Contents for the Digital Edition of AOPA Pilot Magazine - July 2016