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Written by Dave Scott
Correcting the number-one bad habit in the sport
As seen in the March 2020 issue of Model Aviation.

dave scott

Dave Scott is a champion full-scale aerobatics competitor, air show pilot, aviation author, and operates the 1st U.S. R/C Flight School. His manuals and articles feature the specialized training techniques that he has developed—instructing more than 1,700 RC pilots of all skill levels and setting up and test-flying more than 1,000 airplanes at his school. More information about Dave’s books and his flight school can be found at www.rcflightschool.com.

If you have followed my previous articles addressing common bad flying habits, you’ll recall that the chief consequence of bad habits is a higher pilot workload compared with when tasks are performed optimally. Many pilots prematurely plateau because they exhaust all of their "brain bytes" correcting the consequences of their bad habits.

The solution to steady advancement is often not more stick time (e.g., continuing to repeat the same mistakes and hoping for better results), but identifying and correcting the bad habits that often prevent pilots from continuing to improve their flying, conquering wind, diagnosing needed setup changes, and more.

I’ll address the granddaddy of all bad habits, which is constantly fiddling with the ailerons during turns. Roughly 97% of pilots in the sport suffer from this bad habit in the form of unintentional altitude changes during turns, inconsistent positioning and landing setups, struggling to fly in wind, and/or blaming the wind for the fact that no two turns ever work out the same, among other inconsistencies.

constant fiddling

Genesis of the Number-One Bad Habit

The habit of needlessly fiddling with the ailerons during turns goes back to the first turns made by every new pilot. Before the first training flight, a typical instructor’s advice to a new pilot is to keep the turns level and don’t overcontrol.

a figure incorrect turn start input
FIGURE 1

a figure correct turn inputs
FIGURE 2

Without detailed turning instructions, new pilots are on their own, learning through trial-and-error and reacting to what the airplane does. Consequently, every new pilot goes into his or her first turn holding in a small amount of left or right aileron and watching to see what happens next.

As the bank continues to steepen and the airplane starts to lose altitude, the instructor will call for the student to pull up-elevator in an attempt to arrest the descent. With attention now focused on the elevator, both student and instructor are likely oblivious to the fact that the student is continuing to hold in the aileron.

The result is an ever-steepening bank, an increasingly tighter spiral, and confusion about why the airplane is dropping, despite the student obeying the instructor’s commands to pull more up-elevator (see Figure 1)!

This scenario is repeated several more times, and along the way, the focus of the turns becomes what to do when the airplane starts dropping. New pilots at this stage begin to associate descending turns with too steep of a bank and respond by trying to shallow the bank with opposite aileron at the first sign of losing altitude. Shallowing the bank widens the turn, of course, and it often becomes necessary to put some pro-turn aileron back in … and on it goes.

Compounding this activity is the fact that every time the bank angle changes, a different amount of elevator is required to keep the turn level. Steeper banks require more elevator, whereas shallower banks require very little. The ever-changing bank angles make it nearly impossible to keep up with all of the needed elevator adjustments, and as a result, altitude changes during turns become the norm.

Additionally, each altitude change causes an alteration in airspeed and results in other unintended, negative consequences, such as porpoising after a turn (usually attributed to wind).

Most pilots are too busy making adjustments to give any thought to changing their techniques. They continue to make constant adjustments during turns (whether they’re needed or not).

This pattern flies in the face of most other activities. Typically, when we become proficient at something, fewer adjustments are needed because we’re more inclined to do the right thing in the first place. When properly executed, turning a model airplane is no different. If your turns require constant adjustments, it’s a clear indication that you’re doing something wrong!

Proficient/Efficient Turns

The turn procedure used by proficient pilots—the ones who make it look easy—starts with a smooth, yet brief, aileron input to "set the bank" angle. Note that the aileron input is promptly neutralized to prevent the bank from becoming too steep. Up-elevator is then applied and held in to pull the nose into the turn. The elevator is adjusted as needed to keep the turn level throughout (see Figure 2).

In the event of an altitude change during a turn, the appropriate response is to adjust the elevator (not the aileron)! Of course, with only the elevator to be concerned about, keeping turns level is easy, and therefore all of the negative consequences of climbing and descending turns simply vanish.

Proficient pilots understand that the size of the aileron input determines the degree of bank and the size of the turn, as well as how much elevator will be needed to keep the turn level. Proficient pilots proactively input a smaller aileron input, and subsequently pull less elevator to affect a level, wide turn, or they add a larger aileron input and then pull more elevator to affect a level, tight turn (see Figure 3).

They make it look easy because they determine the aileron input that produces the degree of bank (rate of turn) that they are comfortable with 98% of the time. As a result, they are quickly able to determine the amount of elevator to pull each time to keep those turns level, often without needing any additional elevator adjustments.

This procedure entails much more than simply trying to find a comfortable bank angle and maintain level turns. It starts with recognizing that the neutral stick position provides a distinct point from which to gauge the size of each of your control inputs.

If your initial turns are either too wide or too tight, you should aim to increase or decrease the size of your initial aileron input relative to neutral. Or, if you initially pull too much elevator and affect a climbing turn, aim to pull less elevator relative to neutral next time (see Figure 4).

In the event that a turn needs to be tightened, restarted, or widened, the correct procedure is to smoothly apply a single small bump of aileron (in-out) to slightly steepen or shallow the bank angle while continuing to hold in the elevator (see Figure 5).

To avoid overcontrolling (or worse), the aileron input needs to be brief and not held in! Note that needing to bump the aileron during the turn should be fairly rare. If you consistently need to bump the aileron during turns, you should try changing the size of your initial bank input instead.

a figure the size of the initial aileron input used to
FIGURE 3

a figure proficient pilots dont strive to get better
FIGURE 4

Gyro Stabilization

This turn procedure works with most airplanes, but there are a couple of exceptions. Aircraft with a lot of inherent upright stability, such as a high-wing powered glider, are prone to washout of turns and require additional bumps to keep them in a turn.

The other exception is a primary training airplane that features gyro stabilization technology. Gyro stabilization, such as Sensor Assisted Flight Envelope (SAFE) technology, is incorporated into certain airplanes. This technology makes it significantly easier for newcomers to the sport to quickly become successful, independent pilots.

a figure in the event of an unwanted climb or descent
FIGURE 5

Although these models initially require the use of unconventional (simplified) control techniques that will later need to be replaced with conventional control techniques, new pilots are wise to take advantage of the many benefits of starting out on airplanes that utilize the stabilization technology.

SAFE offers a novice pilot the option to start out in Beginner mode. In this mode, bank/roll and pitch are typically limited to no more than 15°, thereby limiting the airplane to mild maneuvering. In the Beginner mode, the airplane also returns to an upright, level attitude the instant the transmitter controls are returned to neutral.

In the Beginner mode, the airplane is essentially steered around the sky like a car. All the pilot has to do is hold the aileron control stick in the corresponding direction that he or she wants the airplane to go. When the model is trimmed for level flight, the stabilization technology automatically keeps turns level without any pilot input.

When the pilot wishes to exit a turn, he or she lets the aileron control stick return to neutral. The airplane will automatically return to level flight.

Switching to the Experienced/Normal mode removes any artificial bank or pitch limits and the airplane does what the pilot tells it to do. Holding in the aileron would cause the airplane to enter a spiral dive and eventually roll inverted. Turns must instead be initiated with a brief (in-out) aileron input to set a bank angle. The turn is sustained and kept level by holding in up-elevator. Exiting the turn requires taking out the elevator and applying opposite aileron to return the wing to level.

Again, new pilots are smart to start out with SAFE technology in the Beginner mode to avoid frequent mishaps or having to depend on others. After they have had some fun and build confidence, they can graduate to practicing conventional control techniques with the airplane still intact.

Some veteran pilots frown upon using SAFE stabilization technology because the control techniques are initially different from the conventional techniques used to fly higher-performance airplanes and aircraft without stabilization. However, these veterans fail to consider that a novice has the option to switch back and forth between having stabilization or not, when ready to learn conventional control.

The point is this: The bad habits of holding in the aileron and subsequently fiddling with the aileron during turns are born out of ignorance. Those who start out in the Beginner mode need not worry about learning any lasting bad habits, as long as they understand how to correctly execute a conventional turn when they’re ready to make the switch.

Conclusion

Proficient pilots don’t endeavor to get better at making corrections. Just like a good driver, proficient pilots apply good control inputs that reduce the need for corrections altogether.

Consider that when your turn inputs are made correctly, the need for additional corrections might not exist. That is when you will be free to think ahead of the airplane, conquer wind, and take on new challenges with greater ease.

Happy flying.






SOURCES:

1st U.S. R/C Flight School

1usrcfs@gmail.com

www.rcflightschool.com

4 comments

Very helpful. I nearly always fail to line up with the runway on my ‘final’ turn and then balloon up instead of having a steady accurate position to land at the end of the runway.

It's incorrect and misleading to suggest that the amount of aileron input directly controls either angle of bank or turn radius. The amount of aileron input (stick displacement from neutral) controls roll rate, and nothing else. Bank angle is determined both by how far and how long the stick is displaced from neutral. Figure 3 is misleading in that either of the depicted stick displacements will result in the steeper bank angle, or graveyard spiral, for that matter. The only difference is how long it'll take to get there. Rate of turn is determined by bank angle alone, but turn radius is a function of both bank angle and speed (groundspeed, as relates to ground track).

You're spot-on as to the correct inputs for proficient turns and your observation that a lot of pilots out here didn't get that message from the outset. I think the more fundamental contributor to fiddling with the ailerons, though, is muddy visualization. The average beginner needs to enter every turn with a clear mental picture of what the airplane is going to look like while it's turning, and what it should look like when it's time to roll out to level. Absent that, he undershoots or overshoots the angle of bank required to make the desired ground track and becomes task-saturated correcting. (Ultimately, the instructor urges "more" or "less aileron" or bank, and the lesson goes in the tank when the beginner takes his eyes off the airplane and looks down at the tx to see where the sticks are.)

Is this what is meant by the term I hear at the field by some old timers -
" Bank and Yank " ?

Dave:

Your recent article on Turning Proficiency in the Feb. 18, 2020 issue of "AMA Today" gives great advice on how to make smooth yaw and roll adjustments resulting in new flight path headings. However, I can't make any of my 23 R/C aircraft perform like your descriptions unless I can find a way to cheat the Law of Conservation of Energy.

The word "throttle" or "thermal" or the mention of "surplus air-speed burn off" does not appear in your article. You do mention many times the use of the elevator during turns to help keep the aircraft altitude constant. Certainly, the elevator is often used to assist in maintaining constant altitude during a heading change.

But without adding kinetic energy to the aircraft (throttle increase, entering a thermal, burning off (converting) surplus air-speed, flying in up-slope wind, etc.) while creating this new heading flight path, there will be an altitude decrease.

The skewing of the gravity vector (a constant) vs. wing-lift vector (a variable) as in a coordinated ruder/aileron roll, and air speed decrease (and resultant lift decrease) caused by the extra air-drag of the aileron and rudder control surface deflections required to overcome pendulum stability along with the additional air-drag and misaligned fuselage form-drag caused by an elevator AOA change (aircraft pitch increase to convert kinetic energy of air-speed to wing-lift in a vain attempt to counteract the above losses) will cause a net decrease of lift and a subsequent altitude loss unless some additional energy (little in a shallow turn- more in a tight turn) is added to the system.

To an experienced pilot, it may seem "second nature" or intuitive to increase throttle settings when performing a constant altitude, constant air-speed turn using a coordinated yaw/roll and elevator decreased-pitch AOA, but a novice pilot (R/C or full-scale) will need to learn throttle management along with how the elevator assists the maneuver.

Best regards,

Frank Horine

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