Congratulations! You’ve soloed your first plane and now you’ve advanced to the point that your takeoffs and landings are no longer knee-knocking brushes with disaster and you are beginning to think that you might start to actually enjoy them some day. So, in the momentary calm between flights you start to ponder what comes next. You know that you want to improve your flying skills, but you just aren’t sure what to do. Relax. We’ve all been there. A good goal for your next level of progress is to learn to reliably control the model in all aspects of flight. And a time-tested way to do this is to learn to fly aerobatic maneuvers. Now, such maneuvers come in a variety of flavors – pattern, scale aerobatics (IMAC), and 3D maneuvers to name a few. But they all have elements in common. And all of them will teach you the skills needed to have better control of your aircraft.

After I had flown my full scale Cessna 182 for a few years I had the opportunity to take a course in “upset training” at an aerobatic school. The basic idea was to learn how to control an airplane in various configurations so that you would better recognize an approaching stall, could recover from a spin, could return to upright level flight after a wake turbulence encounter, etc. I learned to fly a CAP-10B through loops, inverted flight, spins, rolls, hammerhead stalls, and more. That training gave me more confidence in my flying skills – and it was fun, too! The same principle applies to model aircraft. The more you know about recovering from unusual attitudes, the more likely you will be to have the model survive an upset from an unexpected wind gust, for example. My plan is to outline some tips for flying various basic maneuvers in a series of articles. For this month we’ll look at what makes up aerobatic maneuvers and then I’ll cover some techniques for learning how to do a loop. Aerobatic maneuvers can be broken down into segments consisting of loops or parts of loops, rolls or parts of rolls, and straight lines. Add to this that one or more surfaces of the aircraft can be stalled and you can turn a roll into a snap roll, or into a spin if it is done in the vertical direction. Even 3D maneuvers can be treated this way. Count Jose Louis Aresti, a Spanish aerobatic pilot, developed a concise notation for aerobatic maneuvers based on this concept. Each maneuver was broken into its component looping, rolling, and straight-line segments and special symbols were developed for each part. This made it easy to devise new maneuvers and to sketch whole routines in a compact way that could be taped on the instrument panel for easy reference. So, basically, your task is to practice these elements in various combinations. It’s not so hard when you look at it that way!

Rule number one for success is that the pilot should always be ahead of the airplane. You need to be in control of the aircraft, not reacting to what it just did. That means that it is a good idea to have a plan for each flight. This doesn’t have to be a detailed maneuver-by-maneuver description, but it sure helps if you think about what you are about to do before you start. There are lots of piles of balsa and monokote that could have been saved by some simple preflight planning. This goes for both full scale and model flying!

So let’s start with the loop. First, let’s define our terms. We want the loop to be a maneuver where the aircraft follows a circular path that is oriented vertically with respect to the ground. The path should be perfectly symmetric and the aircraft should emerge headed in the same direction as it entered the maneuver and at the same altitude. We wan to be precise here, because that is how you improve your ability to control the aircraft. It helps to think of the loop as consisting of four one-quarter loops, each of which should be identical in curvature. It also helps to picture a clock superimposed on the loop with 12 o’clock at the top and 6 o’clock at the bottom. OK – enter the loop at your predetermined starting point by smoothly applying some up elevator. Your throttle should be at or near full power depending on your particular aircraft. As the plane comes up through the 9 o’clock position the nose should be vertical. As the aircraft passes the 10 o'clock position you should start to relax some of the up elevator. This is necessary in order to keep the loop from tightening up as gravity starts to pull the nose over. If you don’t relax the elevator, the loop will be pinched at the top and the maneuver will become taller than it is wide. Ideally, as the aircraft passes the 12 o’clock position it should be parallel to the ground and inverted. As the plane continues through the 2 o’clock position it is time to ease back on the throttle and to start increasing the amount of up elevator again. If done correctly, the plane will be vertical as it passes the 3 o’clock position. Finally, round out the last quarter of the loop using the appropriate amount of up elevator to bring the plane out level at the starting altitude. During this entire maneuver the wings should not have rolled at all. If some roll input is given you will find that the plane will not track properly and the loop will wander out or in depending on the amount of roll input. Later, you will learn how to do this and also how to add rudder input when flying in a cross wind. But for now, don’t put in any roll input.

It is interesting to compare this description with what happens in a full scale Cap-10 or a Decathlon (both have 200 hp Lycoming engines). You enter the loop at around 120 kts and pull enough up elevator to give an immediate 3 to 3.5 g’s. As you go past the 10 o’clock position you relax some up elevator but not too much. If you go over the top too slowly you can enter an inverted spin. The Decathlon’s fabric wings help here. As you go inverted the fabric on the bottom will start to vibrate if you are approaching a stall – pull some more up elevator as you are inverted and you need to tighten up the loop to keep your speed up. Over the top you feel essentially zero g and then you start to pull more up elevator as you pass the 2 o’clock position. Pull back on the power to avoid over revving the engine and pull another 3 to 3.5 g’s on the exit. Altogether it is very similar to what I described for the model aircraft except that you are inside and you get to feel the g’s. It’s cool! That’s it for this month. In the next link I’ll discuss some rolling maneuvers.