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Written by Jon Barnes
Open source brings versatile functionality.
Product Review
As seen in the February 2018 issue of
Model Aviation.

Bonus video


Frequency and modulation: 2.4 GHz ACCST frequency hopping
Number of channels: 16
Internal memory: 16 MB
Display: 480 x 272 resolution 4.3-inch color TFT
Gimbals: Six ball bearing CNC aluminum with hall-effect sensors
Speakers: Stereo
Ports: 1/8 headphone; mini USB; micro SD card; two trainer ports; external antenna
Battery: 9.6-volt, 2,000 mAh NiMH
Weight: 47 ounces
Dimensions: 9 x 9 x 5 inches
Price: $499.99


• Available in three finishes: silver, gray, and a smudge-resistant, matte-textured scheme.
• Can be run on either the included FrSky operating system or the OpenTX operating system.
• The vivid, color TFT display is viewable in even the brightest sunlight.
• Audible voice annunciations and MP3 file playback over speakers or by using the headphone jack.
• External RF module bay allows use of Spektrum, Futaba, and other non-FrSky receivers.
• Quality ball bearing-equipped gimbals are supremely smooth.
• Built-in telemetry allows pilots to easily monitor and alarm on less-than-optimum RSSI.
• Includes a foam padded, dedicated, lockable hard case.


• Included NiMH battery can only be accessed by removing the back of the transmitter.
• Plastic, rotary menu navigation dial feels inferior to the rest of the hardware that is used on the radio.
• Only a single sheet Quick Start guide is included for the FrSky operating system, and documentation for the ever-evolving OpenTX operating system is very much a work-in-progress.

The impressively bright display is eminently configurable and allows a pilot to customize the screen layout to his or her own taste.

Product Review

There are an ever-growing, diverse number of genres of RC aircraft. Whether a pilot is flying around the sky in an old-school, nitro-powered trainer, roaring through the air with an electric ducted-fan or turbine-powered jet, frenetically flying an FPV-equipped drone a scant few feet above the ground, or specking out a sailplane as it skillfully sniffs out thermals, all RC enthusiasts require a radio system to control their aircraft.

The legacy brands familiar to and used by pilots for the last few decades include Futaba, Hitec, Multiplex, Jeti, Spektrum, JR, Airtronics, and others. A relatively recent newcomer to the world of RC transmitters is FrSky. With the initial release of the Taranis 16-channel 2.4 GHz transmitter, FrSky began claiming market space in a crowded field. How did the company do it? Several key features and capabilities engineered into FrSky transmitters made them instantly popular with value-minded pilots and the do-it-yourself crowd that places a premium on being able to modify at will.

For the former, FrSky included the ability to plug a JR-style radio-frequency module onto the back of the transmitter. This feature allows pilots already well vested in Futaba, Spektrum, JR, and other radio systems to configure the Taranis to work with the non-FrSky receivers that they might already own and have installed in their models. Strategically priced FrSky receivers, which include the ability to monitor and transmit received signal strength indicator (RSSI) telemetry data, capably expedite the willingness of many pilots to slowly migrate from their more expensive legacy receivers that typically lack telemetry.

For the latter crowd, the emergence of an open-source operating system, known as OpenTX, makes FrSky the radio system of choice. Pilots with programming skills, who place a premium on being able to easily modify their transmitter’s operating system, fell in love with the Taranis! Although FrSky does include its own flavor of operating system with its transmitters, most pilots who made the jump into an FrSky transmitter did it because of the perceived benefits offered by a programmer-rich community of OpenTX enthusiasts that was ready to implement the changes suggested by community members.

Since the release of the original Taranis, FrSky has continued to develop and design new models in its transmitter lineup. Released models include the Taranis Plus, the Taranis X9E tray-style radio, the entry-level Q X7, and the Horus X12S. The Horus is the flagship of the FrSky transmitter product line. This feature-rich transmitter is available in a choice of three finishes: silver, gray, and a slightly fingerprint-resistant, matte-textured finish.


Out of the box, the Horus includes a nice, key-lockable, hard-sided case. The included two-point attachment neck strap and AC-powered NiMH battery trickle charger conveniently stow in the case, along with the radio.

FrSky’s inclusion of a compact, padded carrying case protects the Horus while in transit and when not in use.

The only paper documentation that is included with the Horus is a black and white, single-sided sheet of paper. Although the opening paragraph refers to it as “the manual,” it is merely a Quick Start guide. It provides pilots with a brief overview of the Horus’ input switches, sliders, potentiometers, and ports. It also includes a receiver compatibility matrix, binding information, and range-test instructions (the included screen shots are only applicable when using the included FrSky operating system).

No reference is made to the full-length Horus manual, which is available on the FrSky website. The 107-page PDF manual is color illustrated. Pilots can use it to acquaint themselves with the Horus.

Notable features included an integrated GPS module and six-axis gyro/accelerometer sensor (not supported by existing firmware as of yet), an incredibly clear and bright, high-resolution 480 x 272 color, thin-film-transistor (TFT) display, selectable haptic feedback, the ability to annunciate alarms, switch positions, and values using speech, built-in radio frequency telemetry and telemetry logging, and the ability to select on a per-model basis to use either the internal radio frequency deck or an optional external radio frequency module.

A variety of ports are concealed beneath flexible dust covers on the rear of the Horus. These include an antenna connector for the external radio frequency module (RF-SMA), a micro SD card slot (micro SD card not included), a mini USB port, and both Futaba-style and standard trainer ports. A removable plastic panel on the rear of the radio, emblazoned with a chrome FrSky logo, covers the JR-style radio-frequency module bay. The battery charging plug is located on the bottom corner of the Horus, allowing the transmitter to be oriented vertically or horizontally while charging.

Two trainer ports, a mini USB port, and a micro SD card slot are located beneath a protective rubber flap.

Conspicuously absent is any easy way to access to the NiMH battery pack. The only way to access the battery pack is to remove the back of the transmitter.

Six out of eight of the switches used on the Horus are of the three-position variety. The remaining two are two-position switches. One is a spring-loaded momentary unit and the other is a normal switch. A trio of rotary knobs is positioned slightly below the display. The outer two are potentiometers, while the center knob is a six-position encoder switch. The right-hand potentiometer includes a detent for easy indexing to the 12 o’clock position.

Four sliders are included on the Horus. One pair is positioned horizontally on the rear upper corners of the radio, and the other two are oriented vertically on either side of the power on/off button. With the abundance of control inputs scattered across the face of the transmitter, FrSky wisely protects the power switch with a large, red, machined-aluminum flip cover.

The bright red aluminum flip-up cover helps to prohibit pilots from accidentally pressing the power button while in flight.

A pair of circularly oriented buttons is used for programming the Horus. The small, round, plastic rotary switch that is used to quickly advance through menu selections is the only switch that pilots might find lacking. It doesn’t have the same quality feel as the rest of the transmitter.

The Horus is a conspicuously larger and heavier transmitter. A Spektrum DX9 transmitter tips the scales at 30 ounces, and a Futaba 14SG comes in at 34.5 ounces. The comparatively hefty Horus comes in at 47 ounces. Pilots with smaller hands might find it slightly challenging to hold the Horus and reach its more widely spaced control sticks and toggle switches.

An optional set of neck strap mounting brackets can help mitigate the radio’s extra mass. FrSky also offers a nice carbon-fiber tray mounting solution. Both options are available from Aloft Hobbies and relieve pilots from having to actively hold the full weight of the transmitter by transferring most of the weight to the neck strap or the tray’s shoulder harness.

The Horus will still fit into its dedicated case when the optional neck strap mounting brackets are attached; however, this is not the case when the Horus is mounted into the FrSky tray.


The first decision that a pilot is faced with after charging the Horus’ battery and powering it up for the first time is whether to use the included, preloaded FrSky operating software or immediately flash it over to the OpenTX system.

Although the OpenTX firmware does have a moderate learning curve, pilots will find that they can do almost anything with it!

Both operating systems are actively evolving. Before flashing the Horus over to OpenTX, pilots might want to spend a few weekends giving the latest iteration of the FrSky operating system a shakedown. The latest officially released FrSky Horus firmware is version 1.2.21, although FrSky has no fewer than six versions of beta firmware that can be downloaded and installed into the radio. The FrSky operating system might be a good fit for pilots who find themselves perfectly content with the programming that is typical to most mainstream transmitters.

Advanced pilots who like to tinker and tweak their RC gear and electronics will probably choose to switch the Horus over to OpenTX. Since its inception, the operating system has evolved into several revisions. Pilots will need to make sure that they install the correct version for their transmitter. The latest version of OpenTX that is compatible with the Horus is 2.2.0.

The depth of functionality that OpenTX brings to the Horus is astounding. It is difficult, if not impossible, to cover it all in the format of a review article. Features that pilots might find impressive include the option to use actual model aircraft photos, the ability to configure the color screen’s layout, the Companion application that allows a pilot to edit and adjust model setups on a PC instead of in the transmitter, Lua scripting, widgets, and being able to use either your own recorded voice files or any of several comprehensive voice packs made available by the OpenTX community.

In many ways, open-source software offers users a bit of the Wild West experience. Comprehensive, version-specific documentation can be spotty and hard to track down. Although the questions propounded by both new and more advanced Horus users will typically have already been answered, users will have to spend some time searching for these answers. This usually involves spending time in the variety of forum-based OpenTX discussion threads. There is a learning curve involved when you program your first model into the Horus using OpenTX.

The incredibly versatile functionality of OpenTX means that new users will have to think a little outside of the box. The attractive payoff is that becoming proficient at OpenTX programming makes it possible to do almost anything with your models. The sky is literally the limit!


Flying with a new transmitter is akin to trying on a new pair of shoes. Nothing beats the familiar feel and comfort of a favorite pair of shoes. The initial reaction when slipping your feet into any other footwear is that they just don’t feel “right.” Pilots who have flown with the same transmitter for a season or three will need to approach the use of a different transmitter with an open mind, lest they immediately aver that it just does not feel right.

Although the form factor, increased mass, stick spacing, and control input locations of the Horus might take some getting used to, pilots who want an aggressively priced, full-featured, deluxe transmitter will quickly find themselves wowed by the juggernaut that is FrSky’s flagship Horus X12S running the OpenTX operating system.

Pilots who wish to experiment with a drastically less-expensive OpenTX transmitter should have a look at the newly released FrSky Q X7. With a price that is less than 25% of the Horus’ cost, this eminently affordable FrSky transmitter is available in black and white and is a great entry-level radio to get pilots into the world of open-source operating systems.

Pilots who prefer a tray-style radio can slip the Horus into this optional aluminum and carbon-fiber transmitter tray.

—Jon Barnes




Aloft Hobbies
(415) 761-1136


Don't expect much in the way of factory support. My experience with FrSky has been bad.

That’s why you go threw aloft hobbies you can’t beat their support.

FRSKY supplies product through a dealer network, it is not intended that the factory provides support direct to end users. There are several Premium dealers in the USA including Aloft Hobbies mentioned in the article. That company is renowned for the outstanding quality of its service.

Great radio. I've had mine for about 2 years now and it has been bullet proof. Aloft Hobbies is a great retailer and they are very good with any warranty and repair issues. We have 4 X12s and 1 X10 Horus and every one likes them.

That’s why you have to go to aloft hobbies you couldn’t ask for better service and support.

That why you go to Aloft Hobbies for support and service. You couldn’t ask for anything better from Wayne and crew.

So I've been driving, riding, and flying with Futaba radios since I was a kid. I picked up a FrSky (pronounced like two words combined "Free-Sky" ) Taranis Q X7 about 6 moths ago to use with my FPV drones because it was $104, and receivers the size of a finger nail support full 16 channels, two way telemetry, RSSI, PWM for camera/VTX controls, and only cost $16 per receiver. My Futaba T10J costs me $60 for an 8ch or 10ch telemetry enabled receiver. I use my Futaba for my big, more personally valued airplanes, but pretty soon I'll be leaving Futaba altogether. My FrSky experience has been wonderful, and from a "trust" standpoint has not let me down yet, so moving my most valued models from Futaba to FrSky will be a much welcomed break from the pocket burning costs of Futaba, to a far more advanced system that's FrSky's entry level radio, the Taranis X Q7, or I'll pick up a Horse 10s.

For longtime flyers who want more from their radios for X4 X8, even X10 less in costs, check out FrSky. I was skeptical at first, but I'm now fully convinced they are the new top dog at this point, regardless of what you fly, ride, drive, sail, or sink.

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