Review: Horizon Hobby E-Flite UMX Gee Bee-2012/11

The Granville Brothers of the
Granville Brothers Aircraft
Company built some of the most
impressive and famous racing airplanes
in the 1930s, known as Gee Bees. They
used state-of-the-art design concepts to
build some of the best racing airplanes of
that period.
The Gee Bee R2 was designed to
compete in the 1932 air races. It was
built primarily for cross-country racing,
but it was also thought to be a great
pylon racing contender.
The airplane was dangerous and
challenging to fl y, but in the hands
of a skilled pilot the Gee Bee R2 was
exhilarating. Delmar Benjamin built
a replica of the Gee Bee R2 and fi rst
fl ew it in 1991. He learned how to
overcome the Gee Bee’s bad habits, and
accumulated more than 1,500 hours in
the airplane, thrilling crowds at air shows
across the country.
The Gee Bee R2 with its short, round
fuselage, stubby wings, and beautiful
paint scheme, has always been a
desirable RC model to own. However, its
full-scale fl ying traits seem to get worse
with the reduced size, making the RC
model diffi cult to fl y.
With the innovation of the new AS3X
technology, E-fl ite has made the dream
of owning a great-fl ying Ultra Micro RC
Gee Bee R2 come true!
The AS3X System
With the success of the AS3X system
used in ultra micro fl ybarless helicopters,
Horizon Hobby developed an AS3X
system that would enhance the fl ight
characteristics of ultra micro airplanes.
The system gives the model precise
control with smooth handling. It allows
models to be fl own in moderate wind
and reduces the effects of torque, tips
stalls, and turbulence.
The best part about ultra micro
models equipped with the new AS3X
technology is that they have the feel of
a fi nely tuned larger model! The system
will not take away any control from
the pilot. It actually gives a pilot more
control and allows him or her to become
a better pilot.
The UMX Gee Bee R2 BNF model
is packaged in an attractive carrying/
The UMX Gee Bee R2 looks amazing in flight! It has
a big wow factor when flown at the field.
Photos by the author except as noted
AT A GLANCE ...
SPECIFICATIONS
Model type: Skill level: Wingspan: 20.1 inches
Length: 13.9 inches
Flying weight: 3.60 ounces
Power system: outrunner
Construction: Foam and plastic
Battery: 200 mAh 2S LiPo
Propeller: 5.25 x 3.5
Approximate
fl ight duration: 4 minutes
Price: $169.99
PLUSES:
• Beautifully molded foam with attractive
paint scheme
• Nice scale details include fl ying wires,
wheel spats, and pilot
• New AS3X system for smooth, precise
control
• Great-fl ying model
MINUSES:
• Need more fl ying time because 4 minutes
goes by fast!
model is any DSM2/DSMX-compatible
transmitter with four channels or more.
The airplane is a nice size with a
20.1-inch wingspan, and weighs only
3.60 ounces ready to fl y. The model is
constructed from beautifully molded
foam, and has some nice scale features
such as fl ying wires, wheel spats, and
even a pilot bust!
The model is powered with a BL180,
3000 Kv brushless outrunner motor
with a 5.25 x 3.5 propeller. The motor
and battery tray are accessed by a
magnetic cowling hatch that blends
in with the fuselage. Inside the large
compartment, you will fi nd the heart of
the airplane’s electronics: the new sixchannel
DSM2 Ultra Micro AS3X/RX/
Servo/BL ESC unit.
Beneath the model are two new 2.3-
gram performance linear long throw
servos mounted on each wing for aileron
control. The servos were designed to
meet the demands of the AS3X system.
Flight Preparation
After reading through the instruction
manual, I charged the battery. The
included Celectra 2S 7.4-volt DC LiPo
charger requires a 12-volt DC power
source. I used my 12-volt gel cell battery
that I use for most of my charging needs.
Once charged I had to bind the
model’s receiver with my Spektrum
DX7 transmitter. I found the binding
process to be an easy task. With the
transmitter off, I connected the battery
and waited for the receiver LED to
begin rapidly fl ashing. Then I turned my
transmitter on in the bind mode, making
sure that the controls were centered, and
the throttle and throttle trim were in
the low position. After a few seconds my
transmitter was bound and ready to go.
For the fi rst fl ight, I mounted the
battery at the front edge of the battery
tray as recommended. The instruction
manual gives the proper CG location at
26mm back from the LE of the wing at
the root.
To arm the ESC you need to
turn your transmitter on with
the throttle and throttle trim
at its lowest position, connect
the battery, and make sure
that the model is immobile for
at least 5 seconds. This allows the
AS3X system to initialize.
After the AS3X system initializes,
check the fl ight controls for proper
direction and movement. You also must
The UMX Gee Bee R2 comes packaged in this
attractive carrying/storage case, and includes
the Celectra 2S 7.4-volt DC LiPo charger, 200
mAh 2S LiPo battery, and instructions.
storage case, and includes a 200 mAh
2S LiPo cell, a balance charger, and
instructions. All that is needed to fl y the
BL180, 3000 Kv brushless
RTF Sport Scale
Intermediate pilot
Above: A main feature is the new AS3X/RX/
Servo/BL ESC unit. The model is powered
by a powerful BL180, 3000 Kv brushless
motor. Note the size of the radio and
battery compartment!
The cowling
hatch is
magnetic for
easy removal
and blends
nicely with the
fuselage.
Le : The new, stronger 2.3-gram linear servos
mounted beneath the wings were designed to
meet the demands of the new AS3X system.
The UMX Gee Bee R2 features many scale
details such as flying wires, wheel spats,
and a pilot bust. Photo by Ryan Schurman.
Left: The author displays his small UMX
Gee Bee R2 model. A classic clipped-wing
J-3 Cub is in the background. Both are
great-flying airplanes!
check that the controls are centered. The
instruction manual recommends that
you offset the rudder to the right 1mm.
After flying and trimming the model, it
may be necessary to readjust the linkages
so that you are not using excessive trim.
The manual lists the recommended
settings for dual rates and exponential
for the first flights. After setting them, it
was time to fly! Horizon Hobby issued
a product bulletin for the model shortly
after the airplane’s release. On some
models, the overcurrent protection was
being reached on the initial run of a fully
charged battery, shutting off the motor.
To prevent this from happening,
Horizon recommends that you run the
model up to full power on the ground
for 10 to 15 seconds. If the overcurrent
protection is reached, cycle the throttle
and run the motor for another 10 more
seconds. This should bring the battery
voltage down so that it prevents hitting
the overcurrent protection in flight.
I did not have this problem with
my Gee Bee, but I commend Horizon
Hobby for issuing the product bulletin
in a timely manner.
In the Air
I could hardly wait to fly this model.
I had built a micro RC all-balsa version
of the Gee Bee many years ago from a
converted FF kit that did not fly that
well, so this was a good test of the model
and the new AS3X system.
Because I was flying from a grass field,
I gave the Gee Bee a nice hand-launch
and it climbed out with authority. I
added a little up-elevator trim, and it
flew straight and true. I immediately
noticed how smoothly the model flew
with the AS3X system.
I started exploring the model’s
aerobatic envelope. The airplane’s BL
180, 3000 Kv brushless motor easily
pulled the model through some nice
rolls, loops, and inverted flight. The little
Gee Bee looks so cool in flight; it has
some attitude! It has a lot of speed under
full power; after all, it is a racer.
Knife-edge is possible, but I found
that I had to move my battery pack back
to the rear of the tray to move the CG
slightly rearward. I slowed the model to
see how it stalls. When the nose drops
it loses some altitude, but the model
recovers nicely with some power.
I wanted to see how slowly the Gee
Bee could fly. Remarkably, I could slow
the model without any tip stalling and
fly some tight circles. The AS3X system
was working well!
At roughly four minutes, it was time
to land. The motor was pulsing to
indicate that the battery was getting low.
I turned the model into the wind, and
landed safely on the grass runway.
I inspected the model for any loose
flying wires. These wires are not only for
looks; they provide structural integrity
for the wings. If you find a loose wire,
reglue it before your next flight.
I tried taking off from the grass on the
freshly cut field and after a few attempts,
I was able to land on the grass without
tipping over. When landing, carry a little
power until the flare.
If you are flying from a paved runway,
the model tracks nicely on takeoff, with
a surprisingly short ground roll. Landings
are much easier on pavement. Another
nice feature on the model is that the
manufacturer added some plastic
protection on the bottom of the
cowling, and on top of the fin in
case of a nose-over.
Conclusion
This is great-looking, fun model to fly!
I would not recommend the model for a
beginner, but intermediate and advanced
fliers will have a ball with this E-flite
Gee Bee.
The new AS3X system is a winner! It
gives the model a feel of a much larger
airplane. When flying in the wind it
dampens the model’s inputs, and keeps
it from bouncing around. The AS3X
system will change the way people think
about flying small, micro aircraft.
I look forward to the next offering
from Horizon Hobby’s world-class
design team.
—Joe Malinchak
[email protected]
MANUFACTURER/DISTRIBUTOR:
Horizon Hobby
4105 Fieldstone Rd.
Champaign IL 61822
(800) 338-4639
www.e-fliterc.com