Built from simple, inexpensive, common household components shown here, this fan-powered simulator can help the neophyte pilot get familiar with his model and the radio controls in short order.
By E.H. Schoenberg
As seen in the March 1988 Model Aviation.
The first seed was planted last February, when a group of Bend Aero Modelers (BAM) club members sponsored and taught a six-week class for youngsters in building a radio-controlled Glider. The class, conducted under the auspices of the Bend, Oregon Metro Park and Recreation Department, was a hands-on way of stirring young people's interest in the hobby. I was among those in our RC club who organized and taught the class, and my article describing our experiences appeared in the September 1987 Model Aviation.
Not long after the magazine came out, Barry Kurath, president of PASS, the Portland Area Sailplane Society, called to congratulate me on what we'd accomplished with the building class. During the course of our most pleasant conversation, Barry also proposed that, in view of the growing interest in Gliders among the Bend Aero Modelers, the PASS members come join our club for a fly-together or a Gentle Lady contest. Bowled over, I thought, "Wow! These guys, with their winches and contest experience, are experts. They could bring our neophytes and our own· Sunday flier Glider aficionados into the twentieth century!" Of course, we hospitable Bendites would love to have them come over … and the date was set for the 26th of September.
Meanwhile, Barry Kurath wrote a letter confirming our phone conversation, and he included the latest edition of the PASS newsletter, in which a column by Filbert Stump, "For the Beginners," discussed tethered flight tests and other interesting ideas. Stump's concepts dovetailed with the recent concern I'd had about our progress in teaching student pilots how to coordinate hand and eye movement with the RC transmitter control functions. Not only the student Glider pilots, but also our own Bend Aero Modeler power student pilots, could benefit from some extra attention in that area.
The PASS newsletter idea involved tethering a Glider in front of a fan in an attic. This stimulated my thinking. Why not improve upon the concept and make a simple wind tunnel for Gliders? Wouldn't that help our newcomers on the Radio Control scene?
I knew that wind tunnels for models of full-scale aircraft come in all sizes and shapes, and are designed to simulate winds in a broad velocity range. At the same time, I was aware that few of us Bend RCers had either the space or the technical ability to build a bona fide tunnel with that degree of capability and sophistication. However, something fairly basic that we could use to direct a modified airstream over the movable surfaces of an RC Glider might work for us.
What we needed for our just-graduated class of new Glider pilots was a setup that would familiarize the student with the transmitter sticks and with turns. The simulator training device should teach him to anticipate when to stop an overcontrolled turn. It should also help him overcome his dread of that bogeyman of them all—the reversed controlling necessary when the aircraft is coming towards the pilot, as compared to the normal right and left stick movements used when the plane is heading away from him. Another potential use for the simulator would be in helping the inexperienced flier to master the art of turning from downwind leg to base leg (traveling clockwise, a right turn), and then making a final approach—an often-deadly maneuver that still tends to get even many of us older hands in trouble.
The PASS newsletter concept of testing a tethered Glider by blowing an attic fan on it was simplicity itself, and I was sure we could devise a homemade wind tunnel that would suit our purposes. In our case, chance played into our hands, giving our improvising talents a welcome boost—the large cardboard cartons from our new washer and dryer happened to be still in the garage. Using one of the cartons, and adding an 18-in. fan, a card table, some scrap ½ x 2 lathes, a piece of 2 x 4, and a 1 x 12 x 24-in. board, we had our experimental simulator ready to test within two days!
The fan fitted nicely into the dryer carton, which measured 21 in. high, 29 in. long, and 45 in. wide, and with the carton on the card table the height was just right. A hole 12 in. high and 21 in. wide was cut in the bottom, which had then become the front. Pieces of another box were used to make a shroud around the opening and extending out nine inches.
After some testing and refining, our experimental simulator really worked fairly effectively, even surprisingly so! On our first trials, we hung a Glider from the garage ceiling at center-of-gravity, about eight inches from the shroud. This produced adequate movement when right or left turn was signaled. Too much turn, however, took the rudder out of the airstream, and the Glider stayed locked in the turn position. Our solution was to tape four-inch extensions to the shroud sides so that the leading edge of the wing would block excessive turn movement, leaving the rudder still in the airstream where it could return the plane to its former yaw axis. Pitch movement was only barely noticeable, and would have to be learned au naturel in the air.
Yet the turns were still not crisp enough. Aha! Let’s see if straightening out the airstream through egg-crate-type dividers wouldn’t do the trick. A trip to the local liquor commission store provided three bottle dividers, two of which fitted side by side nicely in the exit hole Taped in, they definitely smoothed out the rotating fanned air and improved the turning action of the Glider.
A fellow club member, Dave Gough, who had yet to turn on an RC transmitter (his was ordered and en route to him) happened to come by that evening, and was enlisted in the Simple Simulator project as a novice test pilot for our training system.
A few minutes of right and left turns, correcting stops to straight flight, and stop-and-go S turns acquainted him with what happened to the Glider’s yaw position as it was going away from him. But how would he react if it were coming toward him, requiring him to reverse his control directions so that left stick gave right rudder and vice versa?
It was easy to put him to the text. His pilot’s chair was moved around to the back of our carton so that he was facing the Glider, and the fan, transmitter, and receiver were switched on again. The results were favorable: Responding to the instructor’s commands for right and left turns, Dave soon got over his initial disorientation. Sure, he had the usual moments of confusion; but with the relatively slow-turning Glider giving him time to react, the nerve-wracking fear of a hard landing or a crash was out of the picture. He didn’t have to worry that one misstep at the controls could be the end of a delicate and rather expensive piece of equipment. Sheltered from the vagaries of the real winds, our test pilot was able to concentrate on improving his flying skills.
After 20 minutes of total training, his verdict was: “Now I feel more comfortable with the transmitter, and can start a turn, stop it, fly straight ahead—and do it with the Glider both going away and coming toward me. I think I’ll be better able to control the model now that I have had this simplified simulator time. Hopefully.” Dave is a conservative fellow.
When our neighbor Wally Arbanas came by to see what the action in our garage was all about, he was drafted as our second text pilot. Wally is a novice when it comes to RC flying—he had been out to our field several times but never attempted to fly any of my models—but he’s an experienced military pilot who flew P-38s in World War II.
The first feedback we got from Wally was, “It turns slowly.” Maybe that was his old fighter pilot reflexes, but in any case a fix was clearly needed if the Glider didn’t respond fast enough for him. So we reset the rudder throw to both servo and control horn to absolute maximum, and the result was a much peppier Glider. “That’s more like it,” Wally told us—and we had another novice RC pilot quickly adjusting to the transmitter sticks, turning, stopping the turn, directing the ship while it was flying away from him, and mastering the crucial knack of guiding it back towards himself. Like Dave before him, Wally was spared the traumatic disorientation so commonly experienced by the student pilot trying to cope with switching stick directions.
Now, to get Wally out to the field and into the hobby! But like many experienced pilots he wanted to start out with “his” airplane, the P-38. Alas (but perhaps lucky for him in the end), no P-38s were in stock in our BAM members’ squadrons. “Trainers first, Wally,” I cautioned, glad to see him still nibbling our game.
It was time to try out the system on our peers at the next club meeting. We built a stand for the Glider to hang from, using 1 x 2 x 48-in. laths, a 2 x 4, and a base of I x 12 x 24-in. scrap wood. Our Simple Simulator was now a portable one (albeit dependent on the availability of a station wagon or van).
But for this portability to make sense, we had to have some means of positioning the stand for maximum turning ability in the airstream whenever we changed locations. To get that flexibility, we cut slots in the shroud for the stand to fit in, ensuring that it would be in the correct and best location each time the simulator was set up for flight training classes.
After the finishing touches of paintingthe carton and stand, our Simple Simulator was ready for unveiling. What, we wondered, would our club members say about our almost-no-cost gadget?
"Whatever is that you're bringing in?" was the first question we heard as our wonderful new wind tunnel came in the door. Club members were not exactly overcome, with enthusiasm about this new contraption we were offering them. But when it was set up with the Glider hung from the stand's monofilament line and the fan, transmitter, and receiver switched on, we soon had a line of members queuing up for turns.
First honors went to our president, Ed Verboort, who had been the club's only practitioner of RC Mode I flying—i.e., ailerons/throttle with the right stick, and rudder/elevator with the left stick. "I should change over," admitted Ed, "and this will help my transition from four years of Mode I flying. Started that way for some reason, and never changed. Now I'm afraid to give any instruction to beginners." Score one for the Simple Simulator!
Next up were two guests at the meeting, Jack Turunun and Jack Emerson. Both men were absolute newcomers to RC flying (and both are in their sixties), although Jack Emerson is a retired veteran Navy aviator.
"Now I understand what the transmitter sticks' functions are, and what happens," said Jack Turunun after only a few minutes with the transmitter. When it was coming at him, the Glider caused enough trouble to convince Jack of the need for more simulator time. Ex-aviator Jack Emerson, too, although he showed his flying ability immediately with very smooth turns, was also bothered quite a bit by turns that brought the plane back toward him. “Guess I'm in for more simulator time again," he sighed. "Got a lot of that over the years."
Now came several experienced RC pilots. Loren Anderson is well beyond the need for a simple simulator, but he could remember his early days when he'd sit in a chair with the transmitter and move the control sticks, mentally steering his imagined model into and, with luck, out of maneuvers and unusual attitudes. "I guess I evolved a sort of mental IFR (Instrument Flying Rules) simulator method," Loren said of those days of acquiring his hard-won proficiency, "but this method is better for the rank beginner. I can see an aircraft turning downwind, base, and turn on its final legs with it coming at me as it lands. It would have been useful for me then."
Some of the other experienced pilots in our group weren't so easily satisfied. "It needs elevator response," was Dave Kephart' s reaction. "Perhaps a bigger fan?" Another suggested, ''Why not a bigger box, glassed in with the model inside?" And so the comments escalated.
Of course I defended my homely brainchild. "Heck, after all it's only a Simple Simulator for beginners, and it can be made for almost no cost." Ah well, you can't win them all.
But the general response among the BAM membership was basically positive, and new ideas were already sprouting. "Well, if our line shack were finished and we had power, "'we could' keep it at the field and demo with it." Eric Rustand, a student of our Glider building class and now a regularly attending club member, had the last word: "I wish I'd had a chance to try it out as soon as my Glider was finished. I had to learn the hard way, and my poor old Gentle Lady looks pretty beat up."
Why not make a Simple Simulator for your club, line shack, hobby store, or garage (even your attic)? Your non-RCer friend can enjoy the next-best thing to the real thing—without his having to get insurance first!
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