Among four and six cylinder experimental aerobatic biplanes, the Skybolt is clearly the gold standard. The Skybolt is capable of extreme, on-the-edge aerobatics, yet it is polite, predictable and forgiving in the air and on the ground. The Skybolt is a straightforward, honest, and absolutely beautiful biplane.
These are quotes taken directly from the Steen-aero website, and describe the Skybolt perfectly. It combines a great airshow performer and an everyday flyer into one package.
When I saw that Seagull Models was releasing their own version of this 'more than capable' aircraft, I just had to have one, and the 'Batman' trim scheme is taken directly from N250SB - a full scale Skybolt!
Seagull Models introduced this biplane early on in 2015, and SIG mfg. had a pre-production sample at the Toledo Expo. That pre-production sample, is the one you will see assembled in this review! The Steen Super Skybolt is the third in my series of Seagull reviews.
So grab a beverage and a snack, sit back, and have a look at this great looking bipe - it should be one to watch for at your local field!
All Wood Construction
Covered in Balck and Gold UltraCote (OraCover)
Pre-hinged Control Surfaces
Fiberglass Cowl and Wheel Pants
Removable Wings for Easy Transport
Electric Conversion Parts Included
Painted pilot Included
Sport Scale Model of a Real Aircraft
Lower Wing Must be Removed for LiPo Battery Change if Using Electric Power
Price: $324.49 (Price at Review Publishing Date) Stock Number: SEA237B Wingspan: 61" (1550mm) Wing Area: 1023 in² (66 dm²) Weight: 9-9.5 lbs. (4.1-4.3 kg) Length: 48.2" (1224mm) Center of Gravity (CG): 4.75" (120mm) from the leading edge where wing meets the fuselage
1200-1700 Watt Brushless Outrunner Motor (400-650 kV)
60-80 Amp ESC
2 - 12" Servo Wire Extensions
2 - Y-Harnesses
Thread Locking Compound, CA, and Epoxy
Various Shop Tools
You will need to fabricate a hatch for battery access
Gas/Glow Engine Setup:
4 Channel Radio (minimum), Receiver, and Receiver Battery
6 Standard Servos
.60 2-Stroke Glow Engine OR
15cc Gasoline Engine OR
.90 4-Stroke Glow Engine
2 - 12" Servo Wire Extensions
2 - Y-Harnesses
Glow/Gas Engine Field Accessories
Thread Locking Compound, CA, and Epoxy
Various Shop Tools
As I stated in the introduction, the Skybolt you'll see assembled was a pre-production sample. Therefore, the box had no distinguishing marks on it. Rest assured that if you get this model, it WILL have a colored label with plenty of box art! With the top removed, I found all the pieces bagged and taped to prevent damage during shipping. All parts were accounted for - and believe me, there's a lot of parts!
I love the level of prefabrication done at the Seagull factory - ALL of the decals had been expertly applied, leaving only the assembly for me! The decal work is beautiful, and emulates the pin striping of the full-scale aircraft. The decals have even been applied to the painted fiberglass cowl! Speaking of the cowl, the front opening is huge - I'm betting there won't be any cooling issues!
The wheel pants are also pre-painted fiberglass, and even they have some decal work pre-applied. The center cabanes are pre-painted aluminum, and feel plenty sturdy to handle a good load. Both wings also have aluminum wing joiner tubes - gone are the days of laminated plywood for wing joiners.
Items Used for Completion
From the ground, I will be using my trusty Hitec Flash 7 transmitter. This 7-channel transmitter is very quickly becoming one of my favorite! It feels good in-hand, and the sticks and switches are where they should be. A very nice LCD display makes programming a breeze, and shows me telemetry readouts as well!
A Hitec Optima 9 will be installed in the Super Skybolt - I really like these receivers, as they give me lots of options for channels and servo configuration. I have come to like splitting my elevator servos into separate channels, as it gives me the opportunity to 'fine tune' my control surfaces.
Speaking of control surfaces, I will be using Hitec HS-485HB deluxe standard servos. These are great servos, and available at very reasonable prices. With a ball bearing on the output shaft and 83 oz-in of torque (@ 6.0 V) these servos are great for aircraft up to 12 pounds!
An RCGF 15cc gasoline engine will be at the heart of the beast - with plenty of power on tap, this engine should help the Super Skybolt perform well!
Finishing out the front end is a Falcon 16x8 Beechwood electric propeller. These props not only perform very well, but they look great as well!
A DuBro Fill It Fueling system will be installed to make fueling/defueling the plane easier - this is one product that gets installed in all of my liquid fueled sircraft!
Since I was assembling one of the pre-production samples, I didn't have the manual while assembling the Skybolt. But, I did have a chance to talk with Seagull and help edit the manual you will see in the box. As a result, I'm going to have to say that this is one of the better manuals not completely written in the US - there are lots of illustrations, and the instructions can be well-understood! Any intermediate modeler will have no trouble reading through this manual.
assembly began with attaching the ailerons to the lower
wings. T-Pins were inserted into each of the three hinges,
and the hinges were slid into the aileron and the wing.
I removed the T-Pins, pushed the aileron tight to the wing,
and secured the hinges with thin CA.
small batch of 5-minute epoxy was mixed up and used to install
the fiberglass aileron control horns. A pre-cut slot in
the aileron made this an easy task! While the epoxy was
curing, I attached the Hitec HS-485HB Standard Deluxe servos
to their hatches. A 12" servo extension, secured to the
servo wire, was pulled through the wing using the pre-installed
aileron pushrods were then assembled and connected to the
servo arm and control horn.
After test fitting the shorter aluminum joiner tube into
each lower wing half, I coated the tube and both wing roots
with 5-minute epoxy and assembled the lower wing. A few
pieces of masking tape held the two wing halves together
while the epoxy cured.
ailerons were attached to the upper wing in the same manner
as the lower wings. I then assembled the upper wing by sliding
the long wing tube into the right wing section, followed
by the center section and the left wing. A small machine
screw and washer secure the outer wing sections to the center.
on to the tail, I started by temporarily installing the
lower wing and setting the horizontal stabilizer in place.
After a quick check to see that the wing and stab were parallel,
I cut and removed the covering on the top and bottom of
I knew that the stab fit perfectly, I was able to attach
it to the fuselage using 5-minute epoxy. If you are not
an experienced modeler, I suggest you use 30-minute epoxy,
as it will give you much more time to make sure the stabilizer
and fuselage are properly aligned. When the epoxy had
cured, I mixed up another batch of epoxy to install the
the fuselage now set aside, I installed the control horns
in the two elevator halves and the rudder. Once the epoxy
had cured, the elevator halves were attached to the horizontal
stabilizer using CA hinges and thin CA.
rudder was then attached to the vertical stabilizer using
CA hinges and thin CA, followed by assembling and installing
the three pushrods.
attached the tiller arm to the bottom of the rudder with
two wood screws. The two holes had to be drilled prior to
installation, and a couple of drops of thin CA hardened
the newly drilled holes. Since the tail wheel bracket is
pre-assembled, it was simply attached to the bottom of the
fuselage using a pair of machine screws and washers. I did
add a drop of blue thread locker to each screw to help keep
them tight. The steering springs were bent to the correct
length and installed.
attached the two main landing gear pieces to the fuselage
using a pair of machine screws and locking washers on each
half - a little dab of blue thread locker on each machine
screw will make sure they stay tight. The axle (center)
hole was pre-drilled, but without a manual, I had to figure
out how to attach the wheel pants to the main gear. I decided
to attach the wheel pants with a pair of screws, which we'll
get to in a minute. The axle was secured to the main gear
with a washer and nut on each side of the gear leg. I once
again used a couple drops of blue thread locker to make
sure the axles stay tight.
wheel was secured to the axle with a pair of wheel collars.
I decided the easiest way to attach the wheel pants was
epoxy a small piece of light ply inside the mounting area
of the pant. After the epoxy had cured, I drilled a hole
in the wheel pant and cut the remaining slot with my rotary
tool. The wheel pant now freely slipped over the wheel and
axle. With the plane sitting in my stand, I marked and drilled
two small holes for the attachment screws (marked by the
red dots and arrows in the center photo). With the holes
drilled in both wheel pants, they were then installed.
15cc Gas Engine Installation
of the many reasons I like the Skybolt is its large firewall
- there's plenty of room to install any engine or motor
without any trouble! In this case, I mounted an RCGF 15cc
gasoline engine that I had purchased from www.ibcnyourc.com.
Mike, the owner of ibcnyou, is a stand out guy and a real
pleasure to work with!
I started by mounting the engine to its composite mount
and then fabricating a template. With the template taped
to the firewall, I was able to drill the four holes for
the blind nuts, followed by installing the engine and mount.
was plenty of room below the firewall to secure the electronic
ignition module. I used a piece of DuBro 1 / 4" foam
rubber to isolate the ignition from the airframe. A DuBro
2-56 threaded pushrod and 2-56 ball link made a great choke
rod - this will make it easy to open/close the choke from
the front of the cowl. A 30" 2-56 pushrod and 2-56 ball
link, also from DuBro were used in place of the metric
pushrod included with the ARF. There's nothing wrong with
the one provided - I just like to use ball links on my carburetor
assembled the fuel tank per the instructions using Tygon
gasoline fuel line (not included, but required for gas engines),
and marked the three tank outlets. There wasn't enough room
to get my camera in to show the fuel tank installation,
but believe me, it's in there. The fuel line to the carburetor
was run through the hole in the firewall and connected to
cowl has now been trimmed to allow plenty of air through
- the large opening in the front required a lot of exit
holes! I like the diagonal pattern as it looks a little
more unique than straight cuts in the cowl.
added four 1/2" hardwood blocks to the front of the sub-firewall
- there isn't much wood at this location to attach the cowl.
They were attached using epoxy and a wood screw. Small strips
of card stock and masking tape were used to locate the hardwood
blocks for cowl mounting.
the cowl now secured to the fuselage, I added the included
plastic spinner and a 15x8 Falcon Beech wood propeller.
I love these props - they look great and perform even better!
four servos inside the fuselage were installed next. The
two outer servos are for the elevator halves, the central
rear servo is for the rudder, and the front servo operates
the throttle. I always use DuBro servo screws to
keep my servos in place.
With the elevator halves and rudder centered, I connected
the pushrods to the centered servos. The throttle pushrod
was also connected to its respective servo.
getting close to complete! Wing attachment began with installing
the center cabanes. This involved removing the covering
from the four holes (two on each side of the fuselage) to
allow access to the cabane mounts. The covering was slit
on the top of the fuselage in four spots as well. The cabanes
were then slid into the top of the fuselage and secured
with machine screws through the holes in the sides of the
lower wing was then attached to the fuselage with two nylon
machine screws and the belly pan was epoxied in place -
mine required a little bit of trimming to get a perfect
fit. I then attached the upper wing to the lower wing using
the outer struts and machine screws.
the outer struts in place, it was easy to secure the center
section of the upper wing with machine screws, washers,
and locking nuts. To my surprise, attaching the wings was
very quick and easy!
The painted pilot figure was attached to the cockpit floor
using epoxy, and the aileron connecting rods were assembled
I trimmed and secured the canopy. This task requires a special glue
- I have always used Formula '560' canopy glue, and it has never let
me down! Formula '560' canopy glue is available from ZAP and Frank
That was nearly it - all that remained was checking the balance. The
manual stated to set the Center of Gravity (CG) at 120mm behind the
leading edge of the top wing. This measurement proved to be spot on
when test flying the Super Skybolt.
The day for the maiden finally arrived after a mishap and a couple of months of waiting. I had just finished the Skybolt and was getting ready to load it up for the trip to the SIG field for the 41st Annual SIG fly in. As I was walking out to my garage with the Skybolt, I tripped and ended up falling while carrying the plane. Down we both went, my focus on keeping the bipe from hitting the ground. Unfortunately, I ended up with an aggravated fracture in my ankle, and the Skybolt hit harder than I wanted it to. In the end, I had a trip to urgent care for X-Rays and a braced ankle and the plane suffered from a broken lower wing. To say the least, this day was NOT the highlight of my summer.
Because my Skybolt was a pre-production sample, it was the only one in the US at the time. Luckily, SIG had ordered several of the model, and they were in a container on their way! As soon as they arrived, SIG shipped me the new parts and I was able to complete the Skybolt - again...
So, fast forward to a freshly reassembled airplane. I loaded the Skybolt and a few other planes in my truck and trailer and headed for the field!
I filled the fuel tank and readied the plane for its maiden flight. The RCGF 15cc gasser started easily and was given a few minutes to warm up. The Skybolt was taken off the starting stand and set on the ground. I taxied the plane out and lined her up on the runway. The throttle was advanced, and the RCGF 15cc engine started snorting like a racehorse ready to run.
The maiden take off was fairly straight down the runway, and uneventful. The 15cc gasser proved to be plenty of power for the Skybolt, and had the plane was airborne in a matter of 40 feet. The climb out was kept shallow to avoid any chance of stalling the plane.
At altitude, I checked the Skybolt for any needed trim. Slight down elevator trim was the only correction needed to provide straight and level flight at half throttle. With the trim set, it was time to see what the Skybolt could do!
First up was high speed testing. The RCGF 15cc gasser and 15x8 Falcon prop proved to be the right combination for this bipe - she crossed the field quickly at full throttle but never felt 'too fast'. I listened intently for any hint of flutter as she raced by the pilot's station, but was relieved to not hear anything but the engine.
Slow flight came next, and was much more impressive that I had hoped for. The Skybolt stayed in the air and fully controllable at one-quarter throttle - pretty impressive for an aerobatic biplane! Once again at a high altitude, I tested the stall - the Skybolt got very sluggish before finally dropping the nose into a full on stall. If you're even half awake at the sticks, you'll see a stall long before it happens!
Moving on to my favorite part, I tried some aerobatics. Again, I was impressed! The Super Skybolt handled every sport aerobatic maneuver I threw at it, and it looked beautiful throughout! I was more than pleased with the plane's ability to perform aerobatics.
We're down to one final item on the flight test - the landing. I kept the speed up for the first landing attempt, because, well, you're supposed to with a biplane. The first attempt ended up as a 'go-around' because she came in too fast. So for the second attempt, I throttled back a little more and came in - still a little too hot. The third and final attempt was just right. The throttle was pulled back to just above idle on the downwind turn, and I kept the glide slope shallow. The wheels brushed the tips of the grass at the end of the runway before touching down - MUCH slower than originally anticipated!
With that, the maiden flight was complete, and I was a happy pilot. The Steen Super Skybolt performed flawlessly throughout and showed no bad habits! How often can that be said of an aerobatic biplane?!?! I'd also like to point out that even though the 'Batman' scheme has a lot of black UltraCote, it was easy to keep orientation of the plane while flying!
Models Steen Super Skybolt 15cc ARF
Well, there you have it. The Super Skybolt has been assembled, broken, and reassembled before its first flight. Assembly (and reassembly) were straight forward without a manual, so I can only imagine it'll be easier with instructions at hand! The plane flew great without any bad tendencies - I can't help but to give this plane a nearly perfect score! The RCGF 15cc gas engine and Falcon 15x8 prop performed well and provided ample power for the Skybolt. This combination is outstanding!
Distributed by: SIG Manufacturing
P.O. Box 520
401-7 South Front Street
Montezuma, IA 50171-0520 www.sigmfg.com
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.