Part one of this hover training series, featured in the June/July issue of RC Heli Pilot magazine, detailed all the control techniques required to maintain a stationary hover. This month builds on that knowledge by applying the timeless crawl-walk-run approach to learning to hover in order to achieve maximum results in the shortest amount of time possible.
Dave Scott is a full-scale aerobatic competitor, airshow pilot and has worked in the development of several full-scale aircraft. He founded 1st U.S. RC Flight School and has professionally trained more than 1500 RC pilots of all skill levels. His ground breaking flight training manuals and articles feature the accelerated airplane and helicopter training techniques that he’s developed during his 14,000 hours of instructing experience. More information about his books and flight school can be found at www.rcflightschool.com.
Conventional wisdom says anything worth doing is worth doing right, which has traditionally been interpreted to mean that new pilots should strive to fly the best possible maneuver right away using all the techniques that a highly experienced pilot would use (the equivalent of asking a first grader to learn algebra before learning 2+2) and then chalk up the ensuing struggles to the need for more practice. The more efficient approach recognizes that overall success hinges on first learning good fundamentals, thereby establishing a solid foundation on which to build in the natural progression of refinements necessary for steady advancement.
The quickest way to learn the skills needed to maintain a stationary hover would be to practice them individually before they are brought together. Fortunately, training on a simulator allows a heli pilot to learn the controls one at a time. Note: In the interest of simplicity, we’ll continue to use the customary airplane term “aileron” to describe bank and roll control, “elevator” to describe tilting the heli forward and backward, and “rudder” to describe yaw control.
Start with the heli pointing away from you (tail-in) so that its orientation matches yours as if you were sitting in the cockpit. Prior to lifting off, smoothly “spool up” the rotor rpm’s to the point where the heli appears light on the skids, then smoothly advance the throttle further to lift off. Note that it’s important not to advance the throttle all at once or the increasing torque of the rotor will tend to jerk the heli around and make everything that immediately follows more difficult.
1. Once aloft, the sole objective should be to practice adjusting the throttle to maintain a height of approximately one to two feet (figure 1). Don’t worry about correcting any other deviations; just concentrate on adjusting the throttle to maintain the same height as long as you can or until the heli drifts out of sight. The point is, it’ll take less time to learn to use the throttle when you’re not distracted by anything else.
2. When you are proficient with the throttle, lift off, and while continuing to adjust the throttle to maintain the same height, start correcting left and right movements with small brief bumps of aileron. Remember, the rotor disk is not a good indicator of heli behavior, so concentrate on the body or “heli as a whole” in order to detect movements as early as possible. Continue practicing aileron corrections until you feel comfortable with the aileron and can keep the heli from moving left or right for lengthy periods.
3. Then start concentrating exclusively on correcting forward or backward movements with small brief bumps of elevator. At the point when you’re becoming comfortable keeping the heli stable with the elevator, start introducing aileron corrections between your elevator adjustments and vice-versa. If accomplishing each of these steps seems reasonably simple, you’ll know that you must be doing it right because making things seem easy is always a good sign of proficiency, and consequently you’ll soon be applying all the controls simultaneously.
The single most important thing that any novice can do early on is try to under-control all your aileron and elevator inputs. If you read Part One in the last issue and think that continuing to stress the importance of keeping inputs small and brief seems redundant, the reason it’s done is because holding in inputs is the number one mistake that leads to crashing. And since it takes advanced skills to recover an out-of-control heli, avoiding trouble by making small brief inputs is the only option a novice has. The number two cause of crashes is applying inputs in the wrong direction. But take confidence from knowing that if you keep your corrections small and brief, you can go in the wrong direction without getting into serious trouble. In fact, the future DVD featuring these techniques will demonstrate how a pilot can apply two consecutive bumps in the wrong direction without losing control as long as they’re tiny and not held in. On a similar note, you can take advantage of the fact that small brief bumps only affect the heli slightly to “test the direction,” when you’re not sure which way to go, without much consequence.
When you’re capable of maintaining a stationary hover with the throttle and right stick corrections, making rudder corrections will seem easier. Note that in the ideal world of the simulator, the need for rudder corrections during hover is minimal, so you’ll have to induce deviations with the rudder to create more opportunities to practice rudder corrections (figure 2).
Remember, if things start getting hectic, concentrate on the right stick to reestablish a stationary hover and then use the rudder to correct the body. The first rudder corrections you’ll make in the real world will be to reposition the heli when it occasionally jerks left or right prior to lift-off, especially on smooth concrete. So from this point forward, be ready to make rudder corrections while spooling up rather than waiting until airborne.
Since anyone who can maintain a stationary hover also has the skill to land, you will have landed many times while developing hover skills. However, it’s important that you treat your sim landings as you’ll need to in the real world. For example, due to ground-effect, the heli will act as if it’s riding on a cushion of air when it gets close to the ground, and rather than cutting power and letting it plop to the ground, keep adjusting the throttle to gently lower the heli an inch at a time until it smoothly touches down. Be especially careful not to let the heli touch down if it’s moving sideways, forward, or rearward, because doing so will turn into an expensive bad habit in the world when the heli consequently tips over and proceeds to beat itself up (a.k.a., do the funky chicken). So, even though it’s just a simulator, don’t let the heli touchdown unless it’s vertical.
SIDE & NOSE-IN HOVER
At some point you’ll practice hovering with the side of the heli facing you and then a nose-in hover. During the previous tail-in hover your own perspective matched the heli. Consequently, right aileron moved the heli to your right, and vice versa, and pulling the control stick back toward you moved the heli toward you, and vice-versa. That’s not the case during a side hover; During a side hover, pulling and pushing elevator causes the heli to move to your right and left, whereas right and left aileron moves the heli away or toward you. In order to determine the direction to apply the controls during all the heli’s different orientations, you must forget about your own left and right and switch to thinking about inputting corrections to the heli’s left, the heli’s right, pushing forward toward the nose and pulling back toward the tail (figure 3 and 4). This process doesn’t happen overnight, but thanks to the sim you’ll have plenty of opportunities to practice before flying in the real world.
During a tail-in hover, the heli’s orientation is the same as the pilot. When you start maneuvering beyond tail-in, you’ll have to forget about your orientation and learn to think in terms of the heli’s left, right, front and rear. I.e., bank to the heli’s right or left, push forward toward the nose or pull back toward the tail, almost as if your head (mind’s eye) was above or behind the helicopter.
When you become reasonably proficient at hovering with the side facing you, it’s time to practice hovering nose-in (figure 5 and 6). The most efficient process for learning to hover nose-in is to return to the start of this program and repeat each step with the nose-in.
The maneuver that puts all the skills learned to this point to the test consists of holding in the rudder and performing single and then multiple pirouette rotations or “piros” while making tiny aileron and elevator corrections to remain over the same spot. You may even try adding a steady wind into your simulator as a great way to challenge yourself leading up to flying in the real world. In case you’re wondering, many pros agree that Phoenix flight simulator most realistically mimics real world flying and wind behavior and therefore best prepares pilots to tackle increasing wind speeds as skills improve.
“Translating tendency” is the tendency of a helicopter to drift to the left during hover due to the side thrust from the tail rotor (necessary to counter the main rotor torque). Pilots may find themselves compensating for this in calm conditions by tilting the heli slightly to the right. However, those that seldom have occasion to fly in conditions calm enough for translating tendency to be much of an issue will instead find that correcting for wind almost always takes precedence, especially with smaller helis.
A great exercise to reinforce your wind-correcting skills is to practice continuous pirouettes while bumping aileron and elevator into the wind to prevent wind drift (figure 7). Example: If you establish a tail-in hover in a right-to-left crosswind, you’ll need to bump or hold right aileron against the wind to remain over the same spot. When you start to pirouette, you’ll need to briefly pull elevator when the tail points into the wind, briefly bump left aileron when the other side is exposed to the wind, and push forward elevator when the nose points into the wind, etc., etc.
It’s not uncommon for helicopters to display a tendency to move forward or backward and/or to the side when initiating rudder inputs. Therefore, when conditions are calm, proficient pilots will perform a series of 90- and 180-degree pirouettes without any corrections to note whether the heli is prone to additional unwanted movements when applying rudder, and then input the appropriate elevator and/or aileron correction during subsequent piros to prevent the deviation(s). The decisive quality here is that while most pilots attempt to fly the best maneuver right away and therefore end up making so many corrections that it becomes extremely difficult to spot how to improve the maneuver, proficient pilots initially keep things simple to make it easier to pinpoint what they need to do to make significant strides by the third or fourth attempt. I.E., Pros know that it’s not how you start, it’s how well you finish that counts! Then, by repeating those favorable actions often enough, certain segments of flying start becoming automatic, freeing you up to detect further ways to improve your flying and/or add new maneuvers.
Next time, we’ll cover maneuvering while hovering, which gives a whole new meaning to the analogy that compares helicopter flying to trying to balancing a marble on a bowling ball. But like most challenges, the sense of satisfaction will be that much greater when successful.
Words: Dave Scott