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Written by Fitz Walker
An economical, gas-powered or quiet electric sport model
Product Review
As seen in the May 2018 issue of
Model Aviation.


Model type: Sport
Skill level: Intermediate
Wingspan: 69 inches
Wing area: 640 square inches
Length: 51 inches
Wing loading: 25 ounces per square foot
Weight: 7 to 8 pounds
Power system: 10cc two- or four-stroke gas/petrol engine or equivalent electric motor system
Radio: Full-range, six-plus-channel transmitter and receiver; seven standard-size servos
Construction: Balsa and plywood
Price: $249.99

Test-Model Details

Engine used: Evolution 10GX
Battery: 2S 2,000 to 4,000 mAh LiPo for receiver and engine ignition
Propeller: APC 12 x 6
Receiver: Spektrum AR7350
Servos: Seven Spektrum A6110 HV
Radio: Spektrum DX9
Weight (ready to fly):7 pounds, 8 ounces
Flight duration: 10 to 15 minutes


• Great flying qualities with attractive scalelike looks.
• Easy access to interior components.
• Well built with quick and easy assembly.


• Stock wheels are somewhat bouncy on pavement.
• Several minor errors in instruction manual.

Bonus Video

Product Review

I admit that I’m primarily an electric model flier. Making the transition from glow to electric some years ago, it is now my comfort zone.

I like to try new things, if not simply to gain more knowledge and experience. Although I’ve spent much time running glow engines of all types throughout my modeling years, I’ve never tried a gasoline-powered model engine.

Usually reserved for large models, there has been a movement to manufacture gas engines in increasingly smaller sizes. Add the bonus of using very inexpensive automotive fuel, and it is easy to see why small gas engines are popular with fliers who like their airplanes to make some noise!

Following in Hangar 9’s line of 108- and 53-inch wingspan Valiants is this midsize 69-inch wingspan ARF. Constructed of traditional balsa and plywood, this 10cc-powered Valiant continues the company’s line of scalelike high-wing sport airplanes.

Most of the parts were well packed and individually wrapped in plastic. Parts for both electric and gas versions are included with motor mounts and a fuel tank supplied for the latter. Most of the hardware you will need is already in the box.

The Valiant kit is complete and well supplied with hardware.

The 91-page manual is in several languages and includes black and white assembly photos for every step. There should be no guesswork in assembly.

The model is covered with iron-on film, and if you look closely in the manual, there are part number references for matching UltraCote replacement colors. The attractive red and white motif has accompanying high-visibility stripes on the bottom of the wing and tail.

There was some slightly loose covering on the ailerons and flaps, but that was quickly rectified with a heat gun. Nearly all of the decals are preapplied at the factory.


Assembly starts with the flaps, which are offset hinged via point hinges. The hinge holes are predrilled, so installation is easy. Ailerons and tail surfaces are attached using CA hinges with pre-slotted holes.

The large flaps are offset hinged.

All of the servos in the wing are attached to removable servo plates that screw into place. You will, however, need to drill some mounting holes with a 1/16-inch drill bit. Pull strings are preinstalled inside the wing for easy routing of servo wires. The kit also includes heavy-duty metal clevises for the control surfaces and prebent control rods. The wing halves use an aluminum tube for a spar and nylon thumbscrews for attaching them to the fuselage.

Anyone who has ever built an ARF will find no surprises when installing the tail surfaces. After trimming the covering, epoxy is used to glue everything together. The horizontal tail alignment was perfectly parallel with the wing out of the box.

The tail wheel assembly is a simple, but nice, affair. It all comes prebent and it takes only a bit of epoxy into the rudder and a couple of screws to mount the pivot plate onto the bottom of the fuselage. This was where I noticed a conversion error in the manual. The manual says to use a 2 mm or 5/32-inch drill bit. It should actually be 5/64 inch, otherwise you will drill a hole that is too big.

You are conveniently supplied with a choice of two tail wheel types: foam for quiet operations off of a paved runway, and a rubber one for grass operations. This is a nice, thoughtful touch. Another one is that all of the control surfaces are predrilled for the plastic control horn mounting screws, which saves time.

Next it’s on to the business end of the model. The fuselage has two access hatches: a screwed down top hatch between the wing halves and a magnetic battery/fuel tank hatch that is integrated with the windshield.

Two hatches allow easy access to the Valiant’s fuel tank and radio gear.

This is where the manual splits off depending on whether you use electric or gas power. For those such as I who are using a gas engine, there is an extremely helpful wood plate that keys into the firewall and functions as a drill template for the included motor mounts. It is practically foolproof—even for the exceptionally gifted fools.

The recommended fuel powerplant is the Evolution 10GX 10cc gas engine. This stylish engine has a pumped carburetor, ABC-type construction, and for all practical purposes, looks like a glow engine. Only the protruding spark plug and ignition sensor wire betray its thirst for petrol instead of methanol.

Because it was my first gas engine, I was enthralled not only by the motor, but its accompanying electronic ignition box. This box is fairly small and lightweight and even includes an rpm sensor output for those with telemetry in their Spektrum radios.

The manual details how to mount the engine and its electronic ignition box, which I had no problem finding room for. My only concern was that the truncated firewall did not leave much room for error when drilling the lower two motor mount screw holes. I would have liked a little more wood there.

A handy drill template makes mounting the engine easy. The Evolution engine fits perfectly inverted and awaits cowl trimming.

The prepainted fiberglass cowl has a nice, glossy finish and was easy to cut and trim for the muffler. You must use an exhaust header extension in order to move the muffler away from the side of the cowl. Attaching the muffler with the cowl on is tricky, but with patience, it all comes together.

To be able to prime the inverted engine, I elected to make a small cutout in the lower front of the cowl so that I can reach the carburetor intake with my finger. This should also help improve cooling.

I left the landing gear assembly for last because it is easier to build the model when it is not actively trying to roll itself off of the workbench while you work on it. No surprises here, and I liked the way the fiberglass wheel pants attached to the metal landing gear. There are only two bolts that screw into blind nuts inside the pants. It is simple with little chance of the pants rotating out of position. The included main wheels are foam rubber.

The controls were set up per the instructions, where I noticed another typo in the manual where it states to set the maximum flap deflection to 150 mm. Somehow a “1” creeped in. I’m pretty sure Hangar 9 meant 50 mm because it would be impossible to achieve a nearly 6-inch flap deflection.

I should also note that the Evolution ignition module, Spektrum receiver, and servos all can operate on 6- to 8-volt power. This allows you to use two-cell LiPo or LiFeO4 batteries without needing a voltage regulator. I used a two-cell LiPo battery. This is my first time using such a setup and I found it convenient. Because everything runs off of one battery, at least a 2,000 mAh battery is recommended.

Breaking In

The first step with flying any fuel-powered model is breaking in the engine. I found premixed gasoline at a local hobby store but I needed to add some additional two-stroke oil in order to comply with the engine’s 20:1 oil requirement. The manual recommends using an electric starter to initially start the new engine.

Out of curiosity, I decided to see if I could hand start it (with a chicken stick). After a couple of dozen flips, the Evolution engine sprang to life with a rich, sputtery, but consistent growl.

After a couple of tanks of fuel and some leaning of the high- and low-speed needle valves, the engine actually became pretty easy to hand start. I noted that the exhaust residue was dirty, but that is apparently typical of this engine until it is fully broken in.


Ground tracking on takeoff is good with only a little rudder input needed to keep the aircraft straight. Expect the model to become airborne quickly, even if you don’t use flaps. Drop the flaps slightly and the model is flying by the time the engine has finished revving up. The recommended control rates were a good starting point, with the low rates being mild and high rates fairly lively, but not overly so.

I particularly noted that the aileron response was light to the touch without being twitchy. The power with the 12 x 6 APC propeller was good with a decent vertical ascent despite the engine being slightly rich.

With a couple of clicks of trim to get things straight, I proceeded to get a feel for the Valiant’s aerobatic capability. Rolls were nice and axial, whether on high- or low-rate settings. Loops were equally graceful, although I preferred to do them on high rates. Snap rolls induced a wonderful gyration that wasn’t blisteringly fast, but strangely hypnotic. The same goes for spins. Not pretentious—just a good, honest spin. This airplane really likes to be thrown around.

Rudder authority is better than the stock control setup would suggest, with plenty of power for hammerheads and even sustained knife-edge flight in either direction. The semisymmetrical airfoiled wing flies inverted wonderfully with only a little down-elevator needed to keep things level.

I felt quite at ease making low inverted passes over the runway. No one would call the Valiant a racing machine, but it scoots along nicely at full power. However, slow speeds are where it really shines. Those big, offset flaps generate a lot of lift and slow the airplane to a crawl when they are fully lowered. There is some ballooning when they are initially deployed, but if you feed them in slowly at low airspeeds, pitch-up is pretty tame.

I suggest adding some down-trim mix to further tame it. Stalls with or without flaps are extremely mild and will build a pilot’s confidence. There is no need to be afraid of jerking around at low speeds.

Landings are a nonissue, although be prepared for a surprisingly long glide if you don’t use the flaps. Those who don’t back off the power early in the pattern will need to be prepared to go around as the Valiant glides down the whole length of the runway. I recommend using the flaps on calmer days because they help bleed off speed, even on steep approaches. Right at the flair, the elevator loses some of its authority on low rates, so I prefer to land on high rates.


The Hangar 9 Valiant is a fantastic model for almost all skill levels. Newer pilots should be able to easily handle it on low rates, while more experienced pilots will appreciate its aerobatics capability. Despite being a non-scale airplane, it actually presents in a very scalelike manner and will surely turn heads at the flying field.

The Evolution 10GX has been a fine-running engine with no dead-stick landings and a reliable idle. The power is more than adequate while being fuel efficient. I found the Valiant to be a perfect airframe for my first foray into gasoline-powered models.

—Fitz Walker


Horizon Hobby
(800) 338-4639

(800) 338-4639


(800) 338-4639
Evolution Engines
(800) 338-4639

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