Testing the Zephyr Drone Simulator

By Terry Dunn

A computer-based simulator is one of the most effective and convenient tools to improve your piloting skills and confidence.

Modern aerial-photography (AP) multi-rotors have a lot of pilot-assist features that make them relatively easy for complete rookies to fly. Some practically fly themselves. Yet, people still crash their drones all the time. Many of those expensive pile-ups could be avoided with a little time dedicated to learning the rudiments of flying. It is also important to practice managing the various features of your multi-rotor, so that you do not get flustered.

A computer-based simulator is one of the most effective and convenient tools to improve your piloting skills and confidence. It's the best way to gain flight time and emulate a practical workload without any actual risk. You can practice when the sun goes down and without regard to weather conditions. The best part of using a simulator is that the damage from a crash is instantly repaired by hitting the restart button!

About Zephyr

There are a few flight simulators on the market with varying capabilities and price points. I recently checked out a new sim called Zephyr. Many users will be happy to know that it is compatible with Windows and Mac.

While there is a lot of overlap with the features of other simulators, there are also several unique aspects to Zephyr. I think that the most significant unique attribute of Zephyr is the Learning Management System (LMS). For budding pilots who are learning in a classroom setting, LMS allows an instructor to assign specific training tasks and track the progress of each student. The instructor can even monitor a training flight real-time from another workstation. Zephyr is also available for single users.

Zephyr allows a wide range of controllers to be used. The FlySky FS-T6 (center) was included, but I also used a Futaba 14SG (left) and Interlink Elite (right).

A number of different controllers can be used with Zephyr. The version that I tested comes with a FlySky FS-T6 transmitter, which is an off-the-shelf 6-channel unit made to actually control an RC model. A USB adapter (also included with the sim) allows the transmitter to interface with a computer.

A different sim/controller bundle is available as well. It includes the FlySky FS-i6S transmitter. The big difference between the FS-T6 and FS-i6S is the throttle control. The FS-T6 throttle stays where you put it when you release the stick, while the FS-i6S throttle is spring-loaded to return to center. You'll want to choose whichever style mirrors the transmitter for your multi-rotor.

A third option includes only the USB adapter. It has plugs that interface with several popular RC transmitters. This is a convenient choice if you already have a compatible transmitter. In fact, I performed quite a bit of my testing with the USB adapter hooked to my Futaba 14SG radio.

Lastly, if you already have a compatible USB interface, you can purchase just the software. I was able to use the Interlink Elite controller that was included with my RealFlight V7.5 sim. It worked really well. You can also use common USB gamepads. However, I'm not convinced they would be of much practical use unless your drone also uses a gamepad-like transmitter (most AP drones do not). Muscle memory is a big part of flight training, so you want your training equipment to match your actual flight equipment as much as possible.

Once you've installed the program, you'll need to create an account. You have to log in each time you use the program. The start-up process automatically installs any updates and will not continue until that is complete. Of course, this means that you need an active internet connection to start Zephyr. The program seems to work fine without internet after it has been launched.

Using Zephyr

The sim offers a handful of popular AP quad-rotors to choose from, including the DJI Mavic, Autel Robotics X-Star, and 3DRobotics Solo. The capabilities of each model in the program reflect the features of the actual quad.

I have flown the real thing for four of the seven included multi-rotors. My overwhelming feeling with all of them was that the simulator versions are significantly more responsive to control inputs than the actual models. The flight performance of each model is hard-coded, so you cannot tweak the control response directly in the program. I overcame this by adjusting the dual-rate settings in the FS-T6. I thought that all of the models performed much more realistically (i.e. easier to fly) with the roll and pitch (channels 1 and 2 respectively) dual rates set to 60%.

When I later used Zephyr with my Futaba 14SG, I made similar adjustments to the pitch and roll controls. The Interlink Elite has a preprogrammed dual-rate switch, but it does not seem to have any effect when the controller is used with Zephyr. Even so, the default control settings with the Interlink Elite felt more natural without adjustments.

The good news is that tweaking the dual-rates on the FS-T6 and 14SG is a simple workaround for overcoming the overly-sensitive models in the simulator. Unfortunately, someone totally new to RC may not know:

  1. The simulated models are touchier than real-life

  2. What dual-rates are or how to adjust them

Little things like that reinforce the value of having an experienced modeler to help show you the ropes.

With my control systems squared away, I began digging into Zephyr's training scenarios. There is a tutorial that explains the function of each of the flight controls and has the student exercise them. It is a good introduction for noobs.

A basic tutorial provides a good overview of the fundamentals of multi-rotor control. It's a perfect starting point for new flyers.

The student can then progress to a series of training courses that work on specific flying skills such as holding altitude, sideways translation, landing, etc. You receive a grade at the end of each course. A grade sheet illustrates errors or rule violations that may have made you lose points. The events are timed and this figure counts into the score…you're just not told what the target completion time is. The report card tells you only your course time and time score.

A summary page tracks your grades for all of the courses. You should be a fairly competent pilot by the time you earn a passing grade for every course. I have a ton of multi-rotor flight time, but I had to repeat most of the courses at last once (often many more) before I was able to claim straight A's for the curriculum.

Your flight performance is graded on several of the training modules.

Additional scenarios force you to exercise several skills to obtain the objective. You might have to hover in place while pointing the camera. Or maybe you have to pass through several waypoints in a specific order. The intent is to help your primary flying skills become second nature. With practice, you don't even think about what you're supposed to do. Your fingers just do it.

The default display provides a third-person view of the drone with an inset window showing the first-person view though the drone's camera. You can toggle to make the first-person view primary. The ability to swap perspectives is often helpful with some of the scenarios.

Modules such as this obstacle course demand varied flying skills and force you to manage the workload effectively.

The sim graphics are adequate, but certainly not lifelike, which is fine with me. I don't need photo-quality backgrounds in order to effectively practice control inputs. I suppose that also helps keep the system requirements reasonable. I'm using a mid-level laptop and it runs fine. The only performance issue on my system is a very slight lag in the controls. Inputs that I make on the controller are reflected on the screen a fraction of a second later.

Although Zephyr's graphics are not photo quality, they are more than adequate for pilot training.

Final Approach

Overall, I think that Zephyr is a good tool for earning or sharpening your multi-rotor flying skills. That is especially true if you intend to teach or learn in a group. As far as I know, Zephyr is the only RC simulator that has LMS options for a classroom environment.

Zephyr provides a common sense approach to learning the fundamentals of flight. It also offers exercises that teach you to manage the pilot workload during a flight, so you're always in complete control of the situation. There is no doubt that mastering these skills on the simulator will drastically improve your competency when you're flying the real nuts and bolts hardware.

Terry is a freelance writer living in Buffalo, NY. Visit his website at TerryDunn.org and follow him on Twitter and Facebook. You can also hear Terry talk about RC hobbies as one of the hosts of the RC Roundtable podcast.