Parkzone releases the follow up to their very popular Radian
electric glider. The Radian Pro BNF (Bind aNd Fly) is
ready to go with a motor, ESC, battery, charger, and DSM2
receiver. The Radian Pro sports features usually found in more expensive
The Radian is what's known as an RE or Rudder/Elevator design
and uses a simple 3 channel radio. The Radian Pro however
is a "full house" design and includes both ailerons and flaps.
Since the release of the modestly priced Parkzone Radian, I have
helped a number of people get started flying with them. The light
weight, well manners, and slow flying
characteristics have helped the Radian introduce several people in our club to
R/C soaring and R/C flying in general.
The Radian Pro steps up the game a notch with a ready to fly
full house sailplane. The "Pro" is priced well below what it would
normally cost to get a similarly equipped built up model in the
air. The ailerons allow tight turns in thermals, and the
flaps allow the model to land where the pilot wants it to without
floating into the next zip code.
Bind it to a radio with advanced mixing functions like my JR 11X
and you can expand the flight envelope ever farther with
features like full wing camber, reflex, and crow (air brake) mixing for
even greater precision.
Radian Pro BNF electric sailplane. Price: $249.99 Wing Span: 78.5" (2 meters) Flying Weight as tested: 33 oz
(935.5 grams) ESC Used: 30Amp (Included) Motor Used: 480 size 960kv
(included) Battery used: 3S 1300Mah LiPo
(included) Radio used: JR 11X 2.4 Ghz
DSM2 5 channel radio
Programmable 5 channel DSM2 radio (optional) if you want to
enable advanced mixing options (crow, camber etc)
Phillips screw driver
12 volt power source
Tweezers or hemostats (optional but VERY useful)
got my start in R/C by learning to fly gliders in 1980 like the
Craft Air Drifter II. 30 years later I still love flying
sail planes. In the not too distant past I would have
considered it sacrilege to mount a large battery and motor on
the front of a sail plane. After flying several motor
gliders though, I decided that rigging a winch or chasing a high
start was a whole lot of trouble when I could take a plane out
of my car, plug the wings and battery in, and be in the air in
minutes. Besides, I reasoned, the long slender fuselages
of most sail planes require lead in the nose to balance properly so at
least the extra weight upfront is doing something useful now!
Don't get me wrong, I still have several planes setup for winch,
high start, and even aero-towing, but for maximum flying time
with minimum fuss, motor gliders are the way to go.
The Radian Pro is Parkzone's answer to the multitude of Radian
owners that wanted higher performance and more features.
Parkzone answered with a sail plane with a better airfoil, as
well as the addition of ailerons and flaps. The Pro can be
flown on a 5 channel radio and Y harnesses on the ailerons and
flaps, or can be set up with a computer radio to enable such
advanced features as reflex, camber, and crow mixing.
Battery and balance charger
Underside radio compartment
When the Radian Pro arrived I inspected the packaging and sat
down to read the rather thick manual from cover to cover.
It turns out that only the first twelve pages are in English so
I never made it to the back cover. The products I have
owned or reviewed over the years from Horizon Hobby always come
with above average or better instruction manuals and the Radian
Pro is no exception. Detailed instructions, clear diagrams
and pictures, safety warnings, parts listings, support contact
information, and even flying tips are all included. In
addition to the printed manual, Horizon also makes setup sheets
available on their web site for their popular radios. If you're
a registered owner of a Spektrum DX8 radio you can just download
the pre-configured setup file straight to your radio. Now THAT
is bind and fly!
The Radian Pro arrived extremely well packaged and damage free.
Parts were separated, bagged, and taped down in to form fitting
areas in the packing container. Where tape was used it was
only used on the foam packing material or over a layer of bubble
wrap, it never touched the actual model pieces. A number
of zip ties were also used to hold the pieces firmly in place
during shipping. Anywhere that zip ties crossed the pieces
of the model there was a layer of bubble wrap or cardboard
protecting the model itself.
Receiver and tail servos
30Amp E-Flite ESC
1300Mah 15C LiPo battery
unpacked the model and set about the task of charging the
battery. The supplied battery is a Parkzone 3 cell,
1300mah, 15C LiPo with a balance adapter and comes equipped with
EC3 connectors. The included charger can charge up to two
amps and either two or 3 cell batteries. It's also
equipped with a lighter plug so you can charge from your
automobile. Ensure that your cell count and
charge rate are set correctly (1.3 amps for the included
battery), plug in the battery via the balance tap to the
correct output on the charger and press the button. When
the battery is done the charge will shut off and the green light
will come on steady.
While the battery was charging I inspected and assembled the
model. The Radian Pro is constructed of durable Z-Foam.
While there are no adhesives required to assemble the model, if
you have a mishap Z-Foam may be glued with just about anything
including regular CA. In speaking with my Dawn Patrol
friends that have a lot of foam planes, they claim the best
adhesive to use to repair the Radian Pro is white Gorilla Glue.
The fuselage has two compartments,
one for the motor and battery on the top front of the model, and
one on the bottom with the Spektrum AR600 receiver and the
rudder and elevator servos installed. Both hatches are
held in place with sturdy magnets. I really like the
magnetic hatch, it makes battery access very easy and that's
important to me on an electric model. The bottom hatch is
vented to allow heat generated by the motor and speed
controller. One minor drawback that I found was with the
louvered hatch on the bottom of the plane. If you fly in the early
morning and the grass is covered with dew, when you land on the
grass you can get water in the receiver compartment.
Rudder and tail skid
Completed tail assembly
Also included and already installed are two Y harnesses, one for the flaps and another
for the ailerons. Since I was planning on using crow
mixing I eliminated the aileron Y harness and connected the
second aileron to the auxiliary channel by adding a short
extension. Radios like the DX7 will require a P-mix setup
for dual ailerons; ensure that you use P-Mix 5 or 6 for the dual
ailerons so that the trim function effects both servos.
Higher end radios like the 9503 or my 11X allow you to select
dual ailerons and specify a mate channel and you're done.
There really isn't a whole lot to do to put the airplane
together. The horizontal stabilizer/elevator is slid into
place and affixed with 4 pieces of supplied adhesive tape.
Before securing the tape I installed the wing tube and measured
the stabilizer for center, then I measured the distance from the tip of the
stab to the wing tube to make sure everything was square.
Connect the control surfaces to the recommended holes and you're
done with the tail.
The wings already have the servos installed and rigged, the only
thing to do here is to install the wing rod and connect the
servos. The wing rod is fairly light and appears to be
plenty sturdy and slipped into place with an excellent fit.
I listed hemostats as optional but if you have a set they will
come in handy for hooking up the flap and aileron servos.
The aileron servo wires are conveniently marked with yellow tags
to keep the connections straight. Unlike the Radian which
uses a friction fit to hold the wings in place, the Pro includes
a countersunk phillips screw on each side so that the wings
remain in place during flight. They even included a spare
screw incase you loose one, nice touch Parkzone! Maybe if
they had known they were sending it to me they should have
included 5 or 6 spares.
Aileron sevo installation
Battery installed ready to fly
Ready to program
of programming options
Notice THERML flight mode
There are a number of options available for you.
Basic radio setup. You can set up a basic acro model,
leave the Y harnesses is place and put the flaps on a switch.
This requires at least a 5 channel radio such at the DX6i.
Even with a more advanced radio, you can go this route and put
the flaps on a 3 position switch or slider and get quite a bit
of performance out of the Radian Pro. But if you're an R/C'r
you probably like to tinker so read on...
You can remove the aileron Y harness and use the setup provided
HERE by Horizon for the DX6i to enable flaps and crow mixing
on a switch. Crow mixing raises the ailerons at the same
time you drop the flaps for a very effective airbrake mode.
This lets you dive without picking up too much speed, it also
helps break lift when you're enjoying a great thermal so much
that you realize you are loosing sight of the plane. It
also allows very fine control of your landing approach for
With a 7 channel or better radio such as the DX7 or a 9503, you can use
the setup sheet provided
HERE and in addition to crow and flaps you can also use
camber and reflex control. Camber lets you drop the flaps
and ailerons to increase the lift of your wing. This works well
when flying slow in thermals to give you maximum lift.
Reflex control raises the trailing edge and lets the Pro fly
faster. This comes in handy when you are in sink and want
to scoot to another part of the sky to resume your search for
lift. In addition to camber and reflex the DX7 allows you
to mix elevator compensation for when the flaps are deployed.
As I said earlier in article, if you're the registered owner of
a DX8 radio you can simply download the file provided
HERE and copy it to your radio via the SDCard slot. I
don't have a DX8 to see all what is included but I would have to
think it would have all the goodies listed above.
For owners with an advanced radio like the 9503, 11X, or 12X,
you can really have fun if you want play with serious sail plane
programming. The 11X features 5 flight modes that you can
individually configure dual rates, expo, aileron differential,
rudder to aileron mixing, elevator compensation, pre-set camber
control, slider or switch controlled camber, and a whole range
of features of which I haven't even figured out what the
acronyms mean yet.
One thing that really helped was plugging in the Radian Pro and
sitting it on my work bench while I referred to the manual and
played with the mixing options. Using the flight modes and
MOT or motor option, I was able to enable the throttle stick to
activate the motor in launch mode, but once I switched to
normal, thermal, or reflex mode the motor becomes inactive and
the throttle stick becomes the flap/crow stick that most high
performance sail planes use.
balanced the Radian Pro at 70mm from the leading edge as the
manual suggested, charged the battery, and headed to the field.
gave the Pro a power off, level toss just to check the balance
and trim. I always use a helper to hand launch a motor
glider on it's maiden powered flight just in case. There
was no need to worry solo launching the Radian Pro however.
You can launch it with power out of your hand or just give it a
level toss into the wind and apply power and climb out.
The Radian won't win any races with the Space Shuttle like I
have seen with a few other motor gliders, but it climbs with
authority and reaches altitude quickly.
This isn't the floater that the original Radian is, you actually
have to work a little bit to fly the Pro. One reason is
the lack of significant polyhedral which eliminates the self
correcting tendency of the Radian. It also likes to fly a
little faster and you will probably find yourself using the
motor than you would with the original Radian. If you try
to mush it around, the plane will stall and loose altitude on
you. Recovery is nothing more than letting go of the up
elevator and letting it regain a little bit of speed or adding a
touch of throttle.
We put several 15 to 18 minute flights using the motor
intermittently but without picking up any real lift charging the
battery between each flight. Though the included charger
doesn't give any indication of power consumption, hooking the battery
up to one of my good chargers showed that these 18 to 20 minute
flights were putting between 55 and 65 percent of the capacity
back in. This shows we had plenty of time to spare to
work some lift or make additional motor runs.
If you drop the camber a few degrees or have the flaps on a
proportional channel and crack them a bit, The Radian Pro will slow
down nicely. The rudder and ailerons are quite effective
and coordinated turns are easy to accomplish for minimal loss of
thermal is a bubble of air that is warmer than the surrounding
air. If you picture a bubble rising from bottom of a tank
of water, as it gets closer to the surface it gets larger due
to the decrease in surrounding pressure, you can begin to
visualize what a thermal would look like if you could see it.
To stay in a thermal you need to circle within the rising bubble
and follow its progress as the thermal itself is blown downwind.
can remember catching my first big thermal like I can remember
reeling in my first big fish, it's quite a rush and can be very
addicting. The key is trimming your glider for hands off
flight and keeping your hands off and letting the plane find the
lift. A sharp eyed sail plane pilot will keep an eye out
for what the birds are doing.
Most of us like to use the motor to head up to high start
altitude, shut it down, and start hunting thermals so I gave
that a try. The Pro reacts well to lift and having
ailerons its easy to turn into the lift. If you use the
rudder to circle in the lift a little bit of opposite aileron to
the turn will keep the wings nearly level
and present the most wing to the rising air. Increasing
the camber a few degrees and the Radian Pro will work the light
lift that occurs down low quite well.
The flaps are very effective at slowing the Radian Pro down for
landing. If you have a radio that lets you use crow mixing
the Pro will appear to come to a stop in mid air. We also
dialed in some elevator compensation so that the Pro maintained
attitude through flap deployment.
Landing with or without flaps is very easy with the Radian Pro.
With little wind the flaps allow the airplane to slow to a
controlled stop nearly effortlessly. The Pro handles winds beyond
what I would have expected from a foam sail plane so if you're
flying in the wind, leave the flaps retracted and use the wind
to slow down your ground speed for landing. Crow can be
used for consistent spot landings.
While I wouldn't recommend this as a
beginner plane like the Radian, the Pro is a great step up for
the pilot that wants more features and more performance.
If you have a high end radio but are intimidated by the
sailplane programming, the Radian Pro is a cost effective
platform that you can use to start experimenting with advanced
features as camber, crow, and other mixing.
The Radian Pro assembles easily
and can get in the air quickly. The BNF version includes
everything you need to get in the air with your favorite DSM2
The Radian Pro launches well,
is a respectable thermal ship, and handles wind surprisingly
well. If you're looking for a step up from a 2 or 3
channel glider, that doesn't take a large chunk out of your
modeling budget, give the Radian Pro serious consideration.
The comments, observations and conclusions made in this review are solely with respect to the particular item the editor reviewed and may not apply generally to similar products by the manufacturer. We cannot be responsible for any manufacturer defects in workmanship or other deficiencies in products like the one featured in the review.