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Why Motion Simulation is Here to Stay

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Why hasn’t some simulation enthusiast created a simulator to teach a child how to ride a two-wheeled bicycle? Imagine all the advantages of a simulator like that. You could teach in any weather, day or night, with no more skinned knees or jogging to keep up as they figure it out. And just think of the fun of using the instructor’s panel to throw in a blown tire now and then: “OK, porkchop. What are your memory items?”

The reason it hasn’t been done is the same reason there isn’t a helicopter simulator under a million bucks worth buying, and part of the reason we keep having the same tired argument about whether motion is important to simulation: Motion is hard to do well—and motion is essential to doing it right.

Humor me with the bicycle simulator a bit longer. Developing anything more than a game or traffic-safety trainer would have a cost/benefit or return-on-investment that only a government agency could love. The barrier is simply that a simulator that could help ditch the training wheels would require precise motion beyond what visuals alone could represent. You don’t balance a bicycle by seeing that you are falling; you balance it by feeling that you are falling. 

Learning to ride means making subtle turning motions to keep the bike underneath you; when the bike falls to the left, you turn slightly left, which puts the bike back underneath. Once learned, you do this unconsciously and almost invisibly. Any training device using only visuals would be useless, perhaps even detrimental. By that time you saw you were falling, it would be too late.

Yet learning to ride a bike works because our brains collect all the cues that might be valuable. We watch, feel and listen; integrating whatever information helps us succeed. The brain is lazy—in a good way. Unconscious response to cues frees up the conscious mind for more important tasks. This is millions of years of evolution at work. Integrating physical cues happens whether we want it to or not.

“But wait,” you say, “In real aircraft, you can’t trust your vestibular system for control. That’s why a visible horizon or instruments are required.”

I agree—but this statement completely misses the lesson of bicycle riding. In the airplane, subtle cues alert us to aircraft motion long before it’s detectable on the instruments, or perhaps even the horizon. We learn to respond to the physical cue and look for the correction needed. We learn the feel of that correction being applied.

This inner control loop of responding to accelerations occurs in full-motion simulators and aircraft, but not in fixed simulators. It’s not that fixed simulators teach incorrectly, so much as they teach incompletely. When it comes time for primary pilots to transition to a real aircraft, those with motion experience have an undeniable advantage; they’ve already integrated cues of motion.

The importance of motion for flight training becomes more obvious when we look at helicopters. The bicycle simulator would be for an inherently stable vehicle with only one axis of motion (roll). The helicopter needs roll, pitch, and yaw (like an airplane), but also heave, which is a straight up and down motion. And it must combine them in any combination. And the helicopter is dynamically unstable to boot. It’s like standing on a basketball. Perhaps while bouncing.

That’s the reason no helicopter simulators under a million dollars are worth buying. The three most difficult, dangerous, and time-consuming maneuvers in a helicopter are hovering, ground-reference work, and auto-rotations. All three require motion just as much as a bicycle simulator would because by the time you see the problem, it’s too late.

To be worth the money, helicopter simulators also need superior visuals and control loading in the cyclic. The sub-one-million dollar helicopter simulators lack these as well. The common visual projection systems get so distorted at the edges that it’s impossible to judge how close the skids are to the ground. A cyclic without control loading tells the pilot nothing about the condition of the aircraft or the unseen aerodynamic forces working on it.

Once the helicopter is well into forward flight, it performs largely like an airplane. It’s no surprise fixed simulators handle the task equally well as they do for airplanes, which is to say incompletely.

The FAA’s Human Factors Division and the Department of Transportation’s RITA websites host, among other things, nearly every study ever done by Universities and Governments over the last 40 or 50 years regarding the value, or lack thereof, of motion in simulation. Pick a side on this argument and you’ll find seven studies here to support your point of view.

For example, one of the dozens of studies that support motion’s importance was done by Delft University of Technology for the American Institute of Aeronautics and Astronautics (AIAA) entitled, “Visual-Vestibular Interaction in Pilot's Perception of Aircraft or Simulator Motion.” The authors reviewed research done by them and others watching pilot response to maneuvers and turbulence, specifically watching peripheral visual and vestibular motion perception in tasks that require inner-loop stabilization. They concluded that peripheral visual and cockpit motion cues are of paramount importance in actual or simulated manual aircraft control.

Another study for the Journal of Aircraft entitled, "Response of Airline Pilots to Variations in Flight Simulator Motion Algorithms," stated: "... it was found that there was a definite positive effect on how the pilots perceived the simulation environment when motion was present and there was almost unanimous dislike for the simulation environment that lacked motion.” The authors also concluded that, “Motion is more realistic, thus more iterative and more stimulating." Simulation, like theater, is an exercise in the suspension of disbelief. In order for it to work, the pilot (audience) must be given just enough reality to be fully engaged in the training, and motion promotes that engagement.

Now, I could be accused of “cherry picking” studies here, just as we’ve seen from companies that don’t offer motion with their simulators and commentators seeking validation of personal biases. Yet what none of these studies, pro or con, have looked at is motion’s impact on training in small aircraft and—most importantly—in primary training. This is exactly the basis of studies underway at the Skyport laboratory in San Marcos, Texas. The good news is that evidence in favor of motion comes in all three flavors: physical, testimonial, and circumstantial.

When the Skyport laboratory went into full operation in January of 2012, the list of experiments that it immediately undertook were based, primarily, on the data collected as part of an exhaustive 2011 study commissioned by AOPA. It provided a baseline of costs for training, student retention, hours to completion, and dozens of other valuable statistics on the challenges of flight training in the U.S.

The terrible statistics on student retention are well known, but less well known is the amount of money the average student is spending toward a private pilot certificate or the numbers hours in the logbook. The numbers were so surprisingly large, understanding the impact of an experimental simulator-centric, proficiency based curriculum felt more like a public service than an experiment.

The Skyport trained students (laboratory subjects) to proficiency in a wide range of flight maneuvers in a full-motion simulator, measuring the time to proficiency when transitioning to the airplane. The study mixed maneuvers logically suited to benefit from motion cues, such as steep turns, stalls or crosswind landings, and those not normally associated with motion cues, like instrument approaches or holding heading and altitude.

The preliminary results of those studies were released at last fall's Migration Flight Training Industry and Design Conference with more data to be released at this coming fall’s conference. Two of the most notable findings were, first, that time to proficiency dropped all tasks. Interestingly, seeing time to proficiency decrease for an ILS or other “non-motion” maneuvers required adding turbulence to the simulation. While the total training time of motion simulator and airplane combined did not drop, the time in the airplane was cut in half. The result was dropping the cost of a Private Pilot certificate by about $4000.

That savings would be even more significant if we were training in helicopters. I learned to fly helicopters in a Schweizer 300C at a whopping $360 per hour. I’m not the most coordinated human being on the planet, but I’m not Joe Cocker either. It still took three excruciating days and about eight hours on the Hobbs meter to hold the Schweizer in a “sort-of” hover.

That hover cost $2880 plus instructor time. What if we could train a pilot to hover in a simulator in eight hours, and then transition to the helicopter in only four hours? The cost to the hover now drops to $1880 in a 300C. Make that a serious helicopter that might cost $800 per hour and we’re talking thousands in savings.

But that’s only if the sim had the right motion cuing, visuals and control loading, and didn’t cost millions. We know of a new helicopter sim with all three requirements in development that’s expected to sell for less than $150,000 in the U.S. When it starts testing this fall, we’ll see if it has the same impact our motion sims did on reducing time to proficiency, and the associated cost.

The last factor in favor of simulation has nothing to do with time-to-proficiency or motion’s integral role in interpreting the flying environment. It comes under the heading of “Circumstantial.”

A couple of years after Redbird started shipping its FMX full-motion simulator, the bestselling simulator in history since the Link trainer, we noticed a phenomenon later dubbed the “Redbird Effect.” At airports with multiple flight schools, soon after one flight school purchased a full-motion simulator, some or all of the other schools will order their own. The reason is simple: In competitive situations a motion simulator bestows a competitive advantage. 

As evidenced above, the simulator can reduce training costs and better prepare pilots for the multi-sensory world of the cockpit. These students talk and word gets around. But motion is also just cool. It’s what the consumer (student) wants, and who’s to say they’re wrong? So, trot out your fat logbook and your hand-picked studies and tell them that motion doesn’t matter and see what they say.

Students pay obscene amounts of money for a pilot’s license today. They deserve the best, most effective technology we can give them. They deserve the one that most completely prepares them for the cockpit, delivers the most for the money and that reinforces the sheer “cool factor” of learning to fly. They deserve something that makes the skill of flying an unforgettable, permanent part of who they are.

You know, like learning to ride a bike.

Jerry Gregoire is CEO of Redbird Flight Simulations. Don't expect this is the last you'll hear from him.

Join the conversation.  Read others' comments and add your own.

Comments (10)

Now if we could just get the motion in the simulators correct........

I have about 5 hours in an FMX at 2 different FBO's and many hours in 4 seat airplanes, and the FMX is way more sensitive than the airplane. If you transfer your muscle memory from the FMX to the airplane, you won't be making any corrections at all. Conversely, if you transfer your muscle memory from the airplane to the FMX, you will be way overcontrolling. Instructors have told me this is a problem as you have to relearn for whichever you are "flying", simulator or airplane.

I've also flown the Jay, and I have to say the visual correction more closely duplicates the actual airplane.

Posted by: Rich Bond | August 26, 2013 4:52 AM    Report this comment

I don't agree with Rich's assessment, the issue is reacting to cues, visual, motion and sound, as well as control input. If the issue is motion that is contrary to how the aircraft reacts, for example turn right, the simulator gives you the opposite cue, that's bad. If the issue is the over sensitivity, then that's something different, and something every pilot needs to train himself to react to, not every aircraft flies the same, so the pilot needs to adjust to different aircraft characteristics, so to me that's a good thing, and has been proven out in the Skyport experiment. I have flown all sorts of aircraft and they all fly differently, I have also flown the Redbird FMX, the MCX and the fixed base LD, they all give reasonable control input reactions and this varies slightly for each sim I have flown. It's just a matter of tuning. In fact, the students that train on the Redbirds seem extremely good at trimming the aircraft and are very smooth on the controls.

Posted by: Trevor Evans | August 26, 2013 6:41 AM    Report this comment

I got my helicopter add-on rating several years ago. At that time I was an avid player of a video game called Battlefield 2. The game included an attack helicopter that seemed to have very similar flight characteristics to the real thing. However, since I had never flown a helicopter I couldn't tell for sure. I got very good at flying the computer helicopter (and blowing the crap out of my opponents). I was curious to see if proficiency with the computer would translate into the real thing, so out to the local FBO I went and took a demo flight in a Schweizer 300CBi. Both my instructor and I were amazed that I could hold a hover with little difficulty. In fact, I felt like I could take it around the pattern without any instructor intervention.

It took about four hours for me to get proficient with the all the controls together. The biggest challenge I had with the real helicopter was to coordinate the throttle with engine/rotor RPM, but being able to use collective and cyclic properly from the beginning was all due to my experience with the game. All told I got my add-on in the minimum time required.

I estimate my proficiency with a simple computer game saved me about $2000 on my helicopter training. I'm an absolute believer in the value of simulators, motion or not.

Posted by: Art Jackson | August 26, 2013 2:09 PM    Report this comment

One man wrote eloquently in his thesis about the value of simulation - however imperfect - and championed it when he was a test pilot. Even though there were known limitations it saved countless hours of expensive test flying of often unflyable aircraft and gave one an edge when it came to the real thing.

Later in his career and right up to the last moment - he was flying (and ejecting from) an imperfect simulator his bosses tried to ban as too dangerous. However imperfect it was - it was the closest thing to something he was only going to get one shot at - first time - 238,854 miles away. When an unexpected boulder field appeared in the window and his co-pilot was intoning the equivalent of "minimum fuel" it gave him the edge he needed to pull off a successful landing.

You didn't try telling the late Neil Armstrong that simulation was a waste of time......

Posted by: Graeme Smith | August 26, 2013 4:18 PM    Report this comment

I wrote about this in regards to remote piloting aircraft. Folks want a co-pilot to be in a sterile office sitting at a desk being able to fly a real aircraft without motion. Pilots can fly a plane in a cockpit looking box, and is done many days for UAV's.

There is talk of using the UAV technology for being the co-pilot of a commercial passenger carrying aircraft.


Posted by: Tom Brusehaver | August 27, 2013 1:37 PM    Report this comment

I just don't think I will ever be convinced that brand new student pilots should have anything to do with simulators. I mean they get into flying to fly, not sit in a simulator. I see the value for advanced ratings and training, but they should be out in the air having fun and building real flight hours.

Posted by: Tom B | August 27, 2013 4:16 PM    Report this comment

Actually I think the biggest difference is no fear of death in a simulator , so not the pressure .

Posted by: frank ihle | August 27, 2013 4:36 PM    Report this comment

Having taught dozens of pilots for both Flight Safety and Simuflite in the Falcon10/100 program, let me say that I am definitely a fan of simulation. But as far as motion being supercritical, I have serious doubts, especially when a staff DPE (won't say which company) told me that an experiment had been done wherein the sim was set up backwards in roll, namely, if you rolled left, it tried to simulate the feeling of rolling right and vice versa. None of the pilots in IFR conditions ever picked up on it. This is most probably the result of very emphatic training to ignore all instances of vertigo in the cockpit and 'just fly the instruments". Yet it makes me question how helpful the motion add-on would be in a primary environment. I recently flew a Redbird Simulator and was very impressed with the IFR capabilities and the visuals, especially for a circling maneuver. BUT, as far as helping a student pilot in the landing learning phase, I just don't see its value. The control feedback coming into ground effect and enduring the flare just didn't feel like any light airplane I ever trained anyone in. Will stop there before I add another sentence ending in a preposition. jjd Newtown CT

Posted by: james Denike | August 28, 2013 2:35 PM    Report this comment

As someone who's company is in the business of building simulators with motion systems, Mr. Gregiore has a vested interest in promoting the necessity of motion systems on flight simulators. In fact, one of the arguments put forth in the essay is simply the "gee whiz" factor that will allow the operator to charge more for a motion equipped simulator vs. a non motion sim.

In my opinion there has not been an adequate study of the merits of motion vs. non-motion simulators. This is primarily due to the large cost of doing it properly. I would suggest that an effective study would be to get a fairly large group of prospective ab-initio airline pilots (a few hundred) and train half of them from the ground up with motion based simulators and the other half without. At the conclusion of the training the performance of these pilots would be evaluated in a series of flights in actual aircraft in various conditions and situations (i.e. not just one test) to compare the skills of the two groups.

One of the biggest problems with adequately doing this experiment is that a significant portion of the training of the non-motion students would have to be repeated at the conclusion of the experiment because parts of the training must be done in full motion simulators (Level C and D simulators) under the current training regulations.

I estimate that to do this properly would run in the neighbor of $25 million for 200 pilots.

Posted by: Stefan Sobol | August 28, 2013 4:32 PM    Report this comment

the bicycle analogy is nice however for additional "bicycle ratings" or annual recurrent pedaling the motion is added subconsciously by the experienced bicyclist when appropriate visuals are present. motion is too expensive. sg

Posted by: Stephan Gnecco | August 28, 2013 6:19 PM    Report this comment

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