Sky-High Adventure with the Macintosh, Amiga, & Atari ST
by Charles Gulick
A MODEL AIRPLANE
In the remaining chapters I'll introduce you to a very different concept in flight simulation, one that adds a truly engrossing new dimension to the program. This concept isn't mentioned in your manual, and perhaps it was not a specific intent of the designers of Flight Simulator. But Bruce Artwick and his team at SubLOGIC have given us more than a simulation of flight; they've given us the means to simulate a number of R/C, or radio-controlled, model airplanes.
You've no doubt seen R/C models flown by highly skilled enthusiasts, and perhaps you've flown them yourself. R/C flying is a sport and hobby pursued wherever an open field or an abandoned stretch of road can serve as a runway. You'll see some youngsters flying R/C, but more often you'll see adults, many of them gray-haired, bent reverently over their kit-built or custom models from dawn to dusk on weekends and holidays. And when they're not coaxing engines to start or making emergency repairs, they're gazing skyward and putting their models through maneuvers that take your breath away. All too frequently, there's a screaming dive and crunching crash, and it's back to the R/C workshop to rebuild for a new try. Many enthusiasts have made a lifetime hobby of R/C flying, and when you watch them fly, it's easy to see why.
I'm not an R/C hobbyist, but I've always had a yearning to be. And Flight Simulator, unlike its predecessors, lets you “fly R/C” with almost unbelievable realism. Further, the airplane models we're going to construct can be involved in heart-stopping crashes only to be picked up and flown again immediately. You won't need to invest long hours of construction labor or repair work. You also don't need a perfect day, because you fly indoors. You don't have to wait for weekends or holidays or special weather because you can fly anytime—nights as well as days, winter or summer, good weather or bad.
How much like a radio-controlled model can we make the Cessna? Follow me and see.
Recall TIEDOWN EAGLE/C, and then unpause and turn the aircraft to a compass heading of 277 degrees. Let the compass settle down, and be sure you have that exact heading before you continue.
Pause again, take the control tower view, and press the Backspace key. Then return to the out-the-windshield view.
Click on NAV and POSITION SET and put the aircraft at NORTH 17226.191, EAST 5177.0390, and ALT 0.0. Close the window and unpause. Then, open it again, and position the tower at NORTH 17226.000, EAST 5177.0000, and ALT 40.0000. (Separating operations this way often prevents spurious tower altitudes.)
Unpause to right the display, and then pause again.
Click on VIEW and set the spot plane distance to 150 feet, altitude to 0 feet, and the preference to roll. Position the spot plane off the aircraft's right wing tip and close the window.
Be sure that carb heat is off and the flaps are zeroed.
Now, move the elevator trim needle all the way to the top of the gauge. (In the Mac use the mouse, and in Amiga/Atari use numerous presses of the up elevator key.) Then in the Macintosh push the mouse forward until the needle pops down to the third mark (second short mark) on the gauge; in Amiga/Atari apply 5 qd (press down elevator five times in quick succession).
Next, open the SIM window and then PARTIAL PANEL, and turn off everything. (Yes, everything.) Close the window.
Set the time to 9:30 a.m.
Position the mouse cursor at the top center of what was your instrument panel, and drag what's left as far down as you can. The panel virtually disappears, leaving a big vacant rectangle in its place.
Now, position the mouse cursor at the bottom right corner of the windshield, and drag the main display to the bottom of your screen.
How do you like that?
Next, open SIM, highlight and click on REALISM, and turn off all realism factors. You should not see a solid box in the window. Close the window.
Take the control tower view. But it's no longer a control tower view. It's your view when you're flying R/C from this particular vantage point.
Your scale-model Cessna is sitting in the grass alongside a runway at a scale model airport designed specifically for R/C flying. The airport is modeled after Fremont Airport in the San Francisco Bay Area. You are standing in the middle of the runway.
Save the whole situation as R/C TRNR FREMNT. And (unless you're flying the Mac) move the mouse cursor completely out of the scene into a bottom corner; you won't be needing it for a while.
You now have an R/C training model of a Cessna (although it isn't a model of the Cessna 182), which is designed to help you familiarize yourself with radio-control flying. Your training model has a wingspan of about 36 inches. The engine has a governor that holds the plane's average speed in controlled configuration to about 50 knots (more, of course, in uncontrolled screaming dives). Act as if your gear is non-retractable, the model is not equipped with flaps, and your simple engine does not have carburetor heat. Your elevator is pretrimmed to a neutral position to provide maximum flight stability.
Your R/C transmitter is relatively sophisticated. It has four fully proportional controls: aileron, elevator, rudder, and throttle. You operate these much as you do in the prototype Cessna, but the control reaction is not the same, and you must get used to the differences by actually flying. To steer the model on the ground use rudder, which also functions like the prototype rudder when you're flying.
The primary flying difference between this R/C training model and the prototype is the takeoff procedure. The model airplane is trimmed so that it will take off by itself when it reaches flying speed. Therefore, do not rotate. Because the model has neither retractable gear nor flaps, undertake no gear or flap procedures on the climbout. Further, do not trim down. The pretrimmed model will climb at about 1000–1250 fpm under full throttle. Thus, your takeoff is literally automatic, except for steering as needed.
In flight, you control the model's altitude primarily with the throttle knob, a control on your R/C transmitter box that functions identically to that in the prototype. To stop climbing and level off, reduce throttle while you observe the model's attitude. When it is straight and level, you are at cruise power, which is approximately 1600 rpm. With power at idle, the model descends at a rate of approximately 500–750 fpm. To climb again, increase throttle for the desired amount of climb. To descend at any desired rate, reduce throttle accordingly. Climb and descent rates, like level flight, must be judged visually from your control position on the ground.
The model's approach and landing are handled much as in the prototype, except for the lack of special slowflight or approach trims or airspeeds; the landing speed is only slightly lower than the flying speed. Thus, the landing approach essentially involves throttle reduction, although the model will take a little back pressure before it stalls, permitting you to flare.
You employ elevator in this R/C training model very sparingly; its primary use is to flare on landing. You can use a little back pressure for turns, but it is not necessary. As the plane turns, it loses a bit of altitude but picks up airspeed, so it returns to approximately level flight. Remember that the model will be very close to its stalling speed during the landing approach and that it will survive an imperfect or rough landing far better than it will a stall and crash.
Your R/C transmitter provides two viewing modes, accessed by the C and S keys. Here's how they work:
The C key (C for control) gives you the view from your ground control position and is the standard mode for R/C flying. You are viewing from your ground control position at this moment. However, when the airplane is flying, you can use the regular simulator zoom features to keep it in sight. Think of zoom as if it were a 500-power monocular used from your ground control position, and zoom freely to maintain whatever view you like. To disable the monocular, press the Backspace key; the zoom factor changes to 1.00 and returns you to the “naked-eye” view.
The S key (S for spot) enables the special spot plane view we set up earlier, off the model's right wing tip. In R/C flying we'll call this the “spot follow” view. It shows your model in profile, as if from a chase or camera plane directly off your wing tip. Turn on the spot follow view now. It is as if you were sitting on your haunches and observing your model from a few feet away. Pressing the S key will always give you this picture of your model, as if you were flying along right beside it. However, I encourage you to use the spot follow view as little as possible; learn to control the model visually from your position on the ground.
Press the C key to return to your control position. You are standing on the center of the runway. The runway bearings are 130 and 310 degrees; thus, the numbers are 13/31. While you fly, you will not move from this position, but you will, in effect, “turn” to follow the model so that it will always be at the center of your view.
Now, before you take off, review these few pointers on R/C flying:
Try to keep the airplane close to you so that it is clearly visible without extreme monocular magnification. Do not climb to too high an altitude, and if you do so, reduce your power and descend again. And do not fly at great horizontal distances, or you may completely lose your model.
Do everything possible to avoid crashing. It is not necessary to land on the runway, so avoid violent maneuvers trying to do so. Anywhere you can safely put the airplane down is fine, although you should make a concerted effort to land into the wind. This morning the wind is from the west. The model is pointed toward the correct runway for takeoff and in the correct general direction for landing.
If you're flying the Mac, try to make turns with the rudder pedals while in flight and use the mouse only for throttle control. Rudder alone turns the aircraft and, to some extent, obviates the problem of “accidental” change of elevator position—a distinct disadvantage of mouse-only control. If you do try this, count your applications of the rudder key, or you're likely to lose track of the rudder position. If you get a stall warning on takeoff or in flight, this means your elevator has “slipped” to a higher setting, so add a little forward pressure to correct the situation.
Finally, expect crashes until you develop the special skills and judgments required for R/C flying. Simply try to learn from your mistakes, and go out and try again. (In fact, this R/C trainer model is unlikely to crash if you fly conservatively. With the throttle at idle, it will glide to a reasonably safe, though not good, landing by itself.)
Go ahead now. Apply full power, steer with the rudder control on your transmitter, and your model will take off and fly. Change the monocular zoom regularly to establish good views of the plane while it's on the takeoff roll and when it's in the sky.
The model will take off very quickly and get into a good climb without your touching the controls. Let it get a little altitude, and then start a turn to keep it from flying too far away. Try to fly a more or less rectangular course, and regularly bring the model back toward your ground position.
Remember to reduce your throttle setting to arrest the plane's climb, and then carefully observe its attitude when it's straight and level (as seen from the ground).
Use your naked-eye view frequently to help you judge where the plane is in relation to your surroundings.
When the plane passes directly overhead, it may look like it is spiraling. This is only an optical illusion; don't let it alarm you. Let the plane fly beyond your position before you judge whether you need to make any corrections.
Use the spot follow view once or twice to see how it works. (Try to avoid accidental out-the-cockpit views because they have nothing to do with R/C flying. If you're in trouble, you can take one on the sly. But resolve to do that only in your earliest R/C learning stages, and then only in dire emergencies. Regard out-the-cockpit views as taboo once you're reasonably adept at radio control.)
After you've flown pretty well for a while (interim crashes notwithstanding), try a landing. Try to make it from the east and in the general direction of your ground position. But, again, don't worry about landing on the runway; simply get the model safely on the ground. And when you do, taxi it toward you. As soon as it's close enough, take the naked-eye view. You can bring the plane right up to your feet. (The brakes work too.) Then, turn it, taxi it over, and park it about where you started.
Now, I ask you, is that a beautiful R/C model, or is that a beautiful R/C model?