Saturday, May 7, 2011

All Together Now – Part Two


If you have been following this series of articles, you can now do a loop, a roll, maybe even a few consecutive rolls, and use the rudder to do a bunch of fun maneuvers. Some of them might even be Stall Turns! As you learned each of these individual maneuvers, you have acquired the basis to do all aerobatic maneuvers.

What does that mean? How can a few rolls, loops and stall turns mean I know all about every aerobatic maneuver? Maybe you have been sniffing too much raw fuel these days Bob? Notice the above paragraph reads “the basis” of all aerobatic maneuvers.

When broken down, all aerobatic maneuvers consist of three parts. The first is the straight line. But no one says the straight line has to be level and horizontal. The line can be vertical, or at a 45 degree angle or even at a 60 degree one. A stall turn for example, consists of a straight line up, the rudder turn, and then a straight line down. The Triangle Rolling Loop in Fig. 1 uses six straight lines. Yes, six lines as the straight line across the top is actually made from one line before the roll and then another line after the roll.


Figure 1

The Triangle Rolling Loop also has four looping sections, called arcs. There is the 1/8 of a loop to the 45 “up-line” then a 3/8 loop from the up-line to the line across the top. There is another 3/8 loop from the second line across the top to the 45 deg. down line and then a final 1/8 loop to the straight exit line. Add up all those eights and you find the total is 8/8 of a loop. That’s right. This complicated looking maneuver is just a single loop with some straight lines added here and there.

When you were first practicing to do a loop, probably some of them looked a lot like this instead of a round loop. That is because the Triangle Loop is just a loop where you messed up the elevator inputs. Of course, you have to “mess up” the inputs at precisely the right moments so the up and down lines are exactly 45 Deg.

The final component of this maneuver is the single roll across the top. It is a straight line, roll and another straight line. You have been doing that for a while now. Of course the roll must be centered in between the two, equal length straight lines across the top. So there it is. A complicated looking maneuver but you already know all the basic components. Now it is just a matter of practicing all the components together in their proper positions.


Figure 2

The Cuban Eight in Fig. 2 puts the same elements together differently. Like the Triangle Loop, the maneuver starts with a loop but this loop goes all the way over the top and starts down. It stops at the 45 deg. straight line down with the half roll. Then comes a ¾ loop over the top to the final straight line down with the other half roll. Recovery uses the final 1/8 loop to the exit line.

By now, you are beginning to see how this works. All aerobatic maneuvers are combinations of rolls, straight lines and loops with some rudder work thrown in here and there. Rudder input in a roll, with lots of elevator, yields a snap roll.

You really know it all and can do almost any maneuver with a little practice. Just be sure your practice is at least three mistakes high (about 200 ft.) as most of us will be making two mistakes each time we learn a new maneuver.

So by learning the roll, stall turn and loop in the previous articles, we have shown you how to do everything. That was pretty sneaky but somebody had to do it. But now comes the time to put all these separate maneuvers together. Why do that? First, putting several maneuvers together will make you a better pilot. Most sport pilots do individual maneuvers whenever they feel the airplane is ready, regardless of where they are in the sky. Making the aircraft do the maneuvers you want it to fly, exactly where you want them done, means you are in firm control of your aircraft at all times and that builds your flying skills. Second, it is just way cool to fly a maneuver pattern right at “air show center” as it were. So let’s do a bunch or maneuvers, all one after another, to make a dance in the sky.

This is what I love to do. Most of these maneuvers can be done with a basic trainer. They can be done even easier, and be larger, using an airplane such as the Hobbico’s Avistar 40, the Hangar 9 Arrow or the Midwest Aerobat. Or any other shoulder wing (or low wing) airplane with a semi-symmetrical or symmetrical airfoil. In other words, any good second airplane.


Figure 3

Take off into the wind and do a straight out, gently climbing flight until you are at about 100 feet high. Fly level for about 100 feet, allowing the airplane to gain airspeed. Remain at full throttle and pull straight up for about 20 feet. Use the rudder to rotate the airplane into a wingover, a stall turn with full throttle. This is not a stall turn. Go up and over in a graceful ‘U’ shaped maneuver. You do it at full throttle and keep full throttle until you are at about 100 feet high again.


Photo 1

You go up, fly the “U” over the top away from yourself, rotate through 180 degrees, go down and level off. Now you are out in the field, probably about 100 to 200 feet out from the runway; going back downwind. When you get right in front of yourself, do a loop; maybe do two loops! (Editor: you might want to start with just one loop and work up to two or three loops after a while.) So far you have impressed the heck out of your flying buddies.

After doing the two loops, they were superimposed-weren’t they, continue flying downwind, about 100 ft. high, to a point about 300 feet past yourself. Pull up into a stall turn (see the Sport Aviator article on doing Stall Turns). When you finish the stall turn you will be going upwind (into the wind) just like the take-off. As the aircraft reaches the middle, get set to do a square loop.


Figure 4

Fly past yourself and about 50 feet later pull (“pull” means applying up elevator), a 1/4 loop to vertical “up” for about 100 feet. Then pull into a 1/4 loop to level inverted flight for 100 ft. Maintain full throttle for about 50 ft. to regain airspeed then reduce the throttle to half. Basic trainers will be using about all the “down” elevator they own at this point just to maintain level, inverted flight. After the final 50 ft. of inverted flight, reduce the throttle to idle and pull a 1/4 loop into straight vertical flight down. Remember, you are at low throttle now. When you have gone down about 100 feet, pull another 1/4 loop to again get to level flight; raise the throttle and continue upwind. By now your flying buddies will be roaring their approval. Or thinking an alien being has taken over your transmitter sticks.


Figure 5

Continue upwind to a point about 300 feet past yourself. It is time to head back to air show center. For that, try an Immelman Turn. Do half a large loop and at the top, when you are inverted, level out (stay at full throttle) and do a half roll to upright level flight going downwind. You are quite high now, probably about 200 to 300 feet. In the middle, opposite yourself, do a roll—one complete roll and continue past yourself to the other end of your flight line and do a split ‘S’. That is, from level flight do a half roll; continue inverted for about 10 feet and then, while lowering the throttle, pull up—gently now—and go down in a large half loop to level upright upwind flight.

WOW; No, DOUBLE WOW!


Photo 2 Photo 3

I hope you are getting the idea. You noticed, I hope, that there are two types of maneuvers you are doing: Centered maneuvers and end (or turnaround) maneuvers. You can fly and bore holes in the sky all day long, and have a ball. You can also do an “air show routine” and enjoy yourself even more

Please don’t get me wrong. This level of skill will not come with the first try. Talk to your instructor about what you want to do. He, or She, will be as enthusiastic as you are. What you want to do is to practice each maneuver by itself and as you master a maneuver tack on the next. Soon you will be able to make up a routine of your own that you will enjoy.

This maneuver “schedule” starts with the easiest and safest maneuvers, straight flight to a Wingover, (you do not even need to manage the throttle at first), and progress to more complicated maneuvers using inverted flight and straight down lines. So start practicing in order. As you progress, you will be amazed that the more complicated maneuvers seem easy. That is because you are mastering your aircraft more with each learning step. By the time you can perform the maneuver schedule, in order and reasonably in position, you will have “outgrown” your basic trainer and be ready for a good second aircraft.

When you were learning to fly your instructor kept giving you more to do. As you mastered each skill, you were given another one; and another one. Sometimes you thought that it would never end. It can end or not, it’s up to you.

If a pilot, full-size or model, does not constantly strive to increase skill levels, that pilot’s skill level will diminish. This is a rule of flying. The best way to learn to play chess is to always play against a superior opponent. The best way to become a great pilot is to always try to fly the next, more difficult, maneuver.

A few years ago, I decided that I had gone as far as I could go by myself. I was as good as I could get doing my own thing. There was more to learn so I set about learning what I could.

Entering Pylon contests taught me a great deal. The most important being that speed is not the most important thing! The two things that are the most important are precision and consistency. How we can develop these things is the real question.

As usual the answer is Practice. Practice, Practice and more—you guessed it—Practice. I never did get as good as I wanted but, I did get better.

Now Precision Aerobatics (Pattern) is my thing. This is how I am improving myself. It turns out that if you can fly a straight line, followed by various loops, stall turns and parts of maneuvers like “Cuban Eights,” you will be fully capable of performing the beginners Pattern maneuver schedule. It is called the Sportsman Schedule.

That is all great if you want to compete. This is not a column designed to get you into any type of competition. Most model pilots do not want to compete. But I do believe each of them wants to be the best they can at this sport so, Let’s Put On A Show.

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