By coordinating rudder deflection with the aileron (rudder moving in the same direction), you prevent the nose from skidding to the left. Adverse yaw is thus prevented; banks and corrections, even rolls, will be smooth and axial, and you will feel more connected to the plane.

When a loop-or any maneuver related to one-is performed in a crosswind, the airplane will drift sideways with the wind during the slower portion of the loop. This drift will generally happen as the plane rounds over the top of the loop. Consequently, a loop that was entered on a parallel flight path with the runway will exit downwind-no longer tracking parallel. If you don’t use the rudder, you will have to do a number of corrections afterwards to reestablish the preferred parallel track taken at the start of the loop.

To correct cross-wing drift, apply rudder in the opposite direction the wind is blowing. For example, if the crosswind will blow the plane to the left, a right-rudder wind correction would prevent it. Ailerons are for keeping the wings level before and during a loop. Don’t try to correct wind drift by creating a new [wing] deviation using aileron; sideways wind drift is a function of yaw, not roll.

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DON’T DIVE TO THE RUNWAY
The first bad habit goes back to the way pilots first learned to set up their landings, and it’s why no two landings have ever gone the same since. Most pilots never give thought to flying a specific landing pattern to set up a landing. Instead, they loosely fly downwind, turn around, and try to get lined up and lose altitude before arriving over the runway. Of course, novice pilots would have been flying higher to stay safe, so when the decision is made to land, they are forced to let the nose drop appreciably during the base leg turn in an effort to lose the excess altitude. As a consequence, the airplane comes out of the turn carrying too much airspeed.

Approaching the runway too fast can been seen at clubs across the country in the form of pilots having to perform multiple go-arounds because they can’t get the airplane on the ground without flying or rolling off the end the runway. All too often, frustration and concerns about fuel or batteries running low cause pilots to then try to force the airplane onto the ground at the higher airspeed with the elevator. As a result, even the best fliers in the country would have a hard time touching down smoothly when carrying too much speed, since the tiniest imperfection during the flare will lead to a balloon, a major bounce, gear damage, or worse. (Usually followed by blaming the manufacturer for not making the gear/plane strong enough). Similarly, we’ve all heard pilots complain about high-lift airplanes that tend to “float,” and yet, unless they figured out a way to switch off gravity, a slow-flying trainer should be easy to land in less than 50 feet! Of course, the reason for floating is not the airplane, but letting the nose drop too much and building up excess speed.

Flying too high on the downwind leg and the resulting preoccupation with trying to lose the excess altitude is also the no. 1 reason why pilots struggle to line up with the runway centerline and often end up needing to make last moment corrections followed by a poor flare. Conversely, if a pilot is less consumed with trying to get the airplane down, he’ll be able to focus more on his surroundings and judging whether the plane is lined up, thereby making the flare much easier. Surely you have noticed how much more slowly things seem to happen and how much easier the landing is when the plane arrives over the runway perfectly lined up?! An essential key to setting up better landings is paying attention to flying a lower downwind leg in advance of the turn to final. This frees you up to focus on positioning and coming out of the turn perfectly lined up with the runway. The combination of a good lineup and not fighting to lose altitude will then afford you more time to think about when to idle the motor to affect a touch down near the front end of the runway. Understand that it is standard practice to let the airplane descend slightly before, during, and after the turn, but also avoid building up excess speed and try not to let the nose drop more than a few degrees. If the airplane is not coming down at a sufficient rate to touch down near the front end of the runway, rather than dropping the nose more, a proficient pilot will reduce power to affect a steeper descent without building up excess airspeed. If turning lower to the ground is something that you’re not comfortable with, it would be wise to acquire a more forgiving airplane and work on your fundamental turning technique. Remember, the plane doesn’t know what altitude it’s at, so if you can perform a reasonably level turn at altitude, you should be able to do it just as well closer to the ground.

DON’T APPROACH TOO FAST
The next common landing mistake occurs after pilots are warned to keep up enough flying speed during the landing to avoid stalling, i.e., don’t let the airplane get too slow on approach to landing. Since these warnings usually come from people who in the past let a model get too slow and crashed, the recipient of this advice usually takes it to heart. The $64 million question is, “How do you tell what the right approach speed is, or, how do you tell when the model is getting too slow?”

The reality is that due to varying wind speeds and directions, differences between airplanes, weight, and even the effects of temperature on airplane performance, there is no consistent answer and you won’t be able to tell by appearances. For example, when flying into a strong headwind, a plane can have plenty of flying speed and yet look too slow, thus prompting a pilot to unnecessarily add more power and subsequently struggle to get the plane down. Or, it’s quite common for pilots to stall during landing and blame the crash on a gust of wind rather than a stall because the plane “had plenty of speed,” when in fact they were landing downwind. Of course, if you always flew the same model in the same conditions (e.g., early mornings in calm winds), you could learn what the proper approach speed looks like, but for most that’s not the real world.

In light of the unknown, many pilots will tend to err on coming in for a landing with extra speed, especially when flying a new airplane or after being told that it is safer to land with more speed anytime there’s wind. Once again, instead of being safer, carrying extra speed makes the landing exponentially more difficult and less forgiving. Plus, even if the plane does touch down smoothly, the odds are greater that it will still carry off the end of the runway! I have seen countless landing mishaps when the concern about rolling off the end of the runway became more important than touching down smoothly. The fact is that far, far more landing gears are torn out each year because of carrying too much speed than because of getting too slow.

Consequently, just as all full-scale pilots are taught, it is preferable for the airplane to touch down at the slowest possible safe airspeed. Not only does a slower approach shorten how much runway is used, it lessens abuse on the airframe and minimizes any bouncing if the touchdown is less than smooth. As a rule, the elite pilots who make it look easy use the same general landing procedure regardless of airplane type or wind. First, we’ll establish a lower downwind to make it easier to control the eventual touchdown location. A throttle reduction is made on the downwind leg to begin a gradual descent while typically holding in and adjusting a small amount of up elevator throughout the landing setup to manage a gradual (approximately 3 degree) descent. Then, when we’re confident that the plane will make the runway, we’ll reduce power to idle or close to idle. So how do you judge whether the plane is getting too slow, since you can’t judge the planes true airspeed by looking at it? The answer is that no matter what type of plane you’re flying or what the wind is doing, the best way to determine whether the airplane has enough flying speed or is getting slow is by “feel.” As most of you know, a wing will start to stall (lose lift) when the angle of attack becomes too steep relative to the flight path, and consequently the airflow no longer remains smooth over the wing. A high angle-of-attack stall is typically preceded by the pilot inputting more and more up elevator, usually to try to keep a slow or steep turn from descending too quickly, or to extend a glide. Stalls are therefore almost always preceded by the pilot pulling increasing amounts of elevator. Regardless of how slow or fast the airplane appears, if you ever find yourself having to add more and more elevator in a turn or on final approach and are urged to keep pulling more, don’t! You are likely on the verge of stalling and need to reduce elevator and/or add power to keep from spinning into the ground. Conversely, if you’re not holding in any up-elevator throughout the landing setup, or sense the need to push forward elevator to steepen the descent, you can be certain that the plane is flying too fast. Space does not permit going into all the details, but some might be interested to know that many of the loss of control mishaps that occur during landings that are attributed to getting too slow or gusts of wind are actually caused by adverse yaw. Adverse yaw becomes more pronounced at higher angles of attack, especially when the airplane features a high-lift flat-bottom airfoil wing. Thus, many pilots who encounter control problems during landing—and therefore think they need to land faster—actually need to mix or learn to coordinate some rudder with their aileron inputs.

With all that said, the single best thing that pilots can do to mitigate these problems is so simple that it’s often overlooked. That is, rather than trying to guess what speed to land at, take the airplane up to a safe altitude and slow it down until it stalls. It’s always a thrill to test fly a student’s new airplane and watch his nervous expression change to optimism and confidence when his plane displays milder than expected stall characteristics and remains somewhat controllable even with full up-elevator held in. Conversely, another model might display a sharp tip-stall tendency and a subsequent rapid loss of altitude until the elevator is reduced. While that may not sound very comforting, it reduces the fear of the unknown and does add to the owner’s confidence to at least know what he’s dealing with before attempting a landing. The notable exception to the standard approach procedures described above applies to anyone flying a very lightweight park flyer or foamy. Since very lightweight airplanes have less inertia, completely shutting off the power during a landing can result in the loss of nearly all forward momentum, and thus a loss of control due to the lack of airflow over the control surfaces. You should, of course, test this at a higher altitude before attempting a landing.

As a rule, lightweight models require the throttle to remain above idle nearly all the way to the ground while using the elevator to control the descent rate. Just remember that this technique is specific to landing very light airplanes (and 200mph Starfighters) and you’ll have to literally switch approaches when transitioning to more conventional airplanes. Happy landings!

LOWER APPROACH
A lower downwind leg and throttle reduction prior to the final turn sets up a lower approach. A lower approach takes the guesswork out of judging when to idle the motor since the touchdown will obviously occur not long after cutting the power.

A. Establish a lower downwind leg.
B. Reduce power to affect a gradual descent.
C. Adjust the elevator to maintain a gradual approximately 3-degree descent angle throughout the setup to landing, but not so steep that excess speed builds up.
D. Idle the motor when confident the airplane will touch down near the front end of the runway.

Proper landing techniques
Fine-tune the elevator to maintain a gradual descent to the runway.
If the plane drops below the glide slope needed to touch down near the front of the runway, adjust the elevator to shallow the approach angle. If it appears that the plane still won’t reach the runway, add more power versus continuing to pull more and more elevator.
If the descent is projected to be too far down the runway, rather than pushing the nose down and building up excess airspeed, reduce power to steepen the descent. If that doesn’t work, it will be necessary to fly an even lower downwind leg.

TEXT & ILLUSTRATIONS BY David Scott (rcflightschool.com)
Photo by David Hart (capturedfromthehart.com)

The post SECRETS TO PERFECT LANDINGS – The correct approach speed is key! appeared first on Model Airplane News.

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FIRST THINGS FIRST
When performing a graceful maneuver like the loop, focus your attention on geometry and smoothness. When executing the “loop” portion of this aerobatic maneuver, you want a low-rate setting that has about 12 degrees of elevator deflection, 30 degrees of rudder deflection, 25 degrees or more of aileron deflection and exponential on all surfaces. As a starting place, I recommend you use about 20% of expo and increase it until you are comfortable with how the airplane responds. Keep in mind that adding expo will soften the feel of how your servo reacts around neutral.

Let’s now discuss the snap roll. The snap roll rotation should happen relatively fast, and if you find that your model “barrel rolls” around in rotation, you do not have enough control surface deflection and may need different rates on your radio. Most models will snap with about 15 degrees of elevator, 35 degrees of rudder and 35 degrees of aileron throw, but again, values differ from model to model. This serves as an overview, and fine-tuning your model will be up to you. As I mentioned earlier, use exponential and start with a value of about 35% on all control surfaces and then make any necessary adjustments.

When I perform a maneuver like the avalanche, I keep my model on my low-rate settings for the “loop” portion of the maneuver. Then, when I want to initiate the snap roll, I switch to my high-rate setting. I perform the snap and flip immediately back to my low-rate setting for the rest of the figure. To simplify matters, I use flight modes, which means that all rates can be found on one switch!

AVALANCHE OVERVIEW

Until you are familiar with this maneuver, I recommend you climb to an altitude of about 150 feet. Keep in mind, though, that this altitude will vary depending on the size of your model; this starting point is great for an electric model with a wingspan of about 50 inches.

Once your altitude is established and your airplane is traveling parallel to the runway, increase the throttle and begin a gradual loop right when the model passes the pilot (for future reference, the pilot’s position is called the “center”). Keeping the same radius, it’s critical to perform a snap roll at the top of the loop. If the loop began immediately after the model passed the pilot, the snap should be performed as the model is inverted over the top of the loop and at center. Once the snap roll is performed, the model continues the second half of the loop and exits at the same altitude at which the maneuver began.

Now, let’s simplify the control inputs needed and divide this maneuver into four steps:

1 Begin by climbing to a safe altitude and orienting your model so it’s traveling parallel to the runway. The throttle will vary depending on your model’s power-to-weight ratio and the size of your loop. If your model has a fairly equal power-to-weight ratio, you’ll need to use maximum power, especially if you want to perform a larger loop. Increase the throttle to about 90% for your first attempt, and wait until the model approaches center.

2 If you’re using dual rates, make sure you’re on your low-rate setting. As the model is at center, gently pull back on the elevator control surface to begin the loop. Geometry is the key, and it’s critical to perform a perfect circle. With that being said, you may need to increase your throttle to keep the speed of the model constant. Also, you may need to make various rudder corrections to keep the model at the same distance from you (nine out of 10 times, you’ll need to apply right rudder due to motor torque). Keep the same radius constant throughout, and when the model is almost halfway through the loop, it should almost be at center, but inverted. This is a key moment to flip to your high-rate settings, or what I call my “snap rate condition.”

3 Initiate the positive snap roll by applying full left rudder, left aileron and up-elevator (if performing the snap to the left; otherwise, right rudder and right aileron with up-elevator). After one complete rotation is performed, neutralize inputs and immediately flip back to your low-rate setting and decrease the throttle to about 10% power.

4 Complete the second half of the loop. When the model is 75% done with the loop, it may be necessary to lower the throttle to idle. However, keep in mind that you may need to increase the power again as you are approaching center (the same point at which the maneuver began).

Now that you have learned how to properly execute the avalanche, let’s discuss a few key tips. If you are flying in an extreme headwind, you may need to gradually pull the model up to initiate the loop and then pull back harder once it has completed the first quadrant, as the wind may push you toward center faster than anticipated. After the snap is performed, you’ll need to pull a little harder on the elevator until you are about 80% done with the loop. You then ease off elevator to complete the maneuver as the model is directly in front of you. Whether you are flying in a head-wind, which we just described, tailwind, or crosswind, it is critical for this maneuver to be centered and performed directly in front of you. Make all necessary adjustments so the model always remains at the same depth from you and that it reaches the cardinal points.

Illustration by FX Models

The post Master the Avalanche appeared first on Model Airplane News.

BASIC ROLLS

The basic aileron roll starts by pulling the airplane up into a 10- to 20-degree climb. This way, the pilot doesn’t have to worry about altitude or the ground and can then apply full left- or right-aileron and roll all the way around (Figure 1). The most important step in this sequence is making sure that you’ve neutralized the elevator used to set the climb before you apply aileron. This precaution ensures that the roll remains axial and on the same heading. Novice pilots must be especially careful not to get ahead of themselves by directly applying aileron while holding in the elevator. This can result in a clumsy barrel roll and loss of heading (Figure 2). Once you have initiated the roll, you need to focus all of your attention on preparing to quickly neutralize the aileron the instant the wings approach level.

Since most rolls only take a second or two, you’ll have to wait until after the roll is completed to consider the result and reflect on whether or not you need to make any changes. For example, if you find that your roll finishes lower than where it was started, you might want to try a steeper entry next time. When learning new maneuvers, I’ve found that it’s best not to muddy the waters by making corrections during the maneuver. If there are deviations, you want them to be obvious and to leave no doubt about what you need to improve next time.

While nearly all symmetrical wing airplanes will roll just fine at half throttle, rolls performed at lower airspeeds tend to be more influenced by gravity and, as a result, tend to drop more toward the end. Rolling at higher speeds reduces the influence of gravity and therefore lessens the drop. Applying full aileron also makes the basic roll easier because it’s completed before it has a chance to lose any appreciable altitude.

HORIZONTAL ROLLS

When you’re comfortable with basic rolls, you’re ready to add a bump of down-elevator (push) to keep the airplane level through the inverted portion of the roll (Figure 3). Since the airplane is inverted only for a brief moment during a roll, the down-elevator input will have to be brief as well, i.e., a “bump.” It’s worth mentioning that those who attempt to base their down-elevator input on watching the plane will often end up holding in the elevator too long while evaluating its effect. Consequently, the plane will perform an outside barrel roll, which will result in a loss of heading and altitude (Figure 4). A proper elevator bump input is just enough to keep the roll level without actually being seen. If the bump is seen or causes the airplane to change altitude or heading, it was either too large or, more likely, held in too long. Thus, as a rule, you’ll do better to bump less, rather than more. Remember, refinements, such as the elevator bump, will only help to perfect an otherwise perfectly good basic roll. If the bump of down-elevator causes you to botch your rolls, leave it out until you’re comfortable with the basic roll again. As soon as you’re all set with the basic roll, that’s the time to reintroduce the down-elevator.

As your confidence increases, the addition of the bump of down means you can start to shallow the entries of your rolls. The eventual goal is to pull just enough up-elevator to keep the plane from dropping through the first part of the roll.

CONSECUTIVE ROLLS

The logical progression from a good single roll is to a double (consecutive) roll. Start by pulling the nose up and then commit to holding in the aileron through two complete rolls. Each time the airplane approaches inverted, briefly bump down-elevator (push). As the airplane approaches the start of the second roll, briefly pull up-elevator again (Figure 5). Using the climbing start will make learning when to input the elevator bumps at the appropriate times much easier. When you have mastered the timing of the elevator, you can then easily start to shallow the entry.

While the type of elevator inputs used during rolls are predetermined, i.e., brief bumps, you’ll need to watch the airplane to determine when to input them: “Inverted, upright, inverted, upright.” Remember that the elevator bumps need to be applied individually at the appropriate times. If you go directly from one bump into the next prematurely, you’ll cause the roll to change heading. Keep in mind that you can save hours of practice by taking some time to rehearse on your transmitter and to input individual elevator bumps (in-out) while continuing to hold in the aileron (Figure 6). When you do fly, all you’ll have to concentrate on is when to apply each bump.

ADVANCED UPRIGHT SLOW ROLL

Few maneuvers truly demonstrate pilot skill like the slow roll. You don’t see slow rolls performed by stunt pilots or those who feel equipment upgrades and programming are substitutes for flying skills. The day that you can perform a slow roll the length of the flying field is the day you can truly call yourself a good aerobatic pilot!

After mastering horizontal rolls with timely elevator inputs, you’re ready to start holding in less aileron to slow the roll rate and add rudder during the knife-edge portions of the roll to keep it level. First, keep in mind that it doesn’t matter if the top or bottom of the airplane is facing you; the rudder should always be applied in the “opposite” direction of the roll/aileron input. The rudder is then applied in the “same” direction of the roll entering the final knife-edge. Thus, if you’re rolling right, the opposite left rudder is smoothly applied to maintain altitude through the first knife-edge. Remember to smoothly push down-elevator through inverted and apply right rudder (same direction as the roll) through the final knife-edge (Figure 7). Keep in mind the correlation between the amount of aileron you’re holding in and the pace of the rudder and elevator inputs: The slower the roll rate, the slower you’ll need to apply and take out the rudder and elevator inputs. This is where applying maximum stick tension and paying attention to your control inputs really helps in comparison to merely reacting to the airplane. Be sure to note that the rudder inputs should be just enough to maintain level flight. Visible yaw is not the object; the object is to locate and repeat the control inputs that consistently produce the best results.

The most common error during slow rolls is neglecting some or all of the required elevator inputs and keeping the roll level with larger earlier rudder inputs. Not only can neglecting the elevator result in descents, but applying large rudder inputs before the wings are noticeably banked can also initiate a slight turn. At every skill level, the most influential factor and what dictates the quality and ease of the remainder of the roll, is the roll’s entry. It’s crucial that you input a small amount of up-elevator at the start of the slow roll to prevent it from dropping. You should also delay inputting the rudder until the wings are banked at least 30 to 45 degrees. Don’t forget to smoothly push forward elevator through inverted to keep the plane level before “same” rudder is introduced when approaching the final knife-edge.

BOTTOM LINE

The success of any maneuver, even advanced ones, hinges on good fundamentals. Advancing pilots often assume that any difficulties they run into will require learning more involved techniques or more stick time to solve. In truth, it’s often just the opposite. If you experience difficulties attempting to add refinements to your rolls (or any other maneuver), get reacquainted with the basics and reaffirm the foundation you need to propel yourself beyond the trouble spot. Practice can only make perfect if you maintain a solid foundation on which to build. Happy flying!

Text & Illustrations By Dave Scott, 1st U.S. R/C Flight School

The post Flying Precision Rolls: The secrets to smooth, well-positioned maneuvers appeared first on Model Airplane News.

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A good landing starts out with a good landing traffic pattern. Start your landing pattern by entering the crosswind leg and then turn into the downwind leg. Turn into the base leg, start your descent and then set up your final approach. All your turns should be 90 degrees.

In a crosswind landing, you should set up a crab heading angle that produces a straight tracking path. The stronger the crosswind, the larger the crab angle needs to be.

A smooth and consistant approach angle is also very important. Use throttle to control the descent rate and keep the wings level. Aim for an imaginary spot just above the runway, and cross the end of the runway at an altitude of about 10 to 15 feet.

The post LAND LIKE A PRO appeared first on Model Airplane News.

BASIC ROLLS

The basic aileron roll starts by pulling the airplane up into a 10- to 20-degree climb. This way, the pilot doesn’t have to worry about altitude or the ground and can then apply full left- or right-aileron and roll all the way around (Figure 1). The most important step in this sequence is making sure that you’ve neutralized the elevator used to set the climb before you apply aileron. This precaution ensures that the roll remains axial and on the same heading. Novice pilots must be especially careful not to get ahead of themselves by directly applying aileron while holding in the elevator. This can result in a clumsy barrel roll and loss of heading (Figure 2). Once you have initiated the roll, you need to focus all of your attention on preparing to quickly neutralize the aileron the instant the wings approach level.

Since most rolls only take a second or two, you’ll have to wait until after the roll is completed to consider the result and reflect on whether or not you need to make any changes. For example, if you find that your roll finishes lower than where it was started, you might want to try a steeper entry next time. When learning new maneuvers, I’ve found that it’s best not to muddy the waters by making corrections during the maneuver. If there are deviations, you want them to be obvious and to leave no doubt about what you need to improve next time.

While nearly all symmetrical wing airplanes will roll just fine at half throttle, rolls performed at lower airspeeds tend to be more influenced by gravity and, as a result, tend to drop more toward the end. Rolling at higher speeds reduces the influence of gravity and therefore lessens the drop. Applying full aileron also makes the basic roll easier because it’s completed before it has a chance to lose any appreciable altitude.

HORIZONTAL ROLLS

When you’re comfortable with basic rolls, you’re ready to add a bump of down-elevator (push) to keep the airplane level through the inverted portion of the roll (Figure 3). Since the airplane is inverted only for a brief moment during a roll, the down-elevator input will have to be brief as well, i.e., a “bump.” It’s worth mentioning that those who attempt to base their down-elevator input on watching the plane will often end up holding in the elevator too long while evaluating its effect. Consequently, the plane will perform an outside barrel roll, which will result in a loss of heading and altitude (Figure 4). A proper elevator bump input is just enough to keep the roll level without actually being seen. If the bump is seen or causes the airplane to change altitude or heading, it was either too large or, more likely, held in too long. Thus, as a rule, you’ll do better to bump less, rather than more. Remember, refinements, such as the elevator bump, will only help to perfect an otherwise perfectly good basic roll. If the bump of down-elevator causes you to botch your rolls, leave it out until you’re comfortable with the basic roll again. As soon as you’re all set with the basic roll, that’s the time to reintroduce the down-elevator.

As your confidence increases, the addition of the bump of down means you can start to shallow the entries of your rolls. The eventual goal is to pull just enough up-elevator to keep the plane from dropping through the first part of the roll.

CONSECUTIVE ROLLS

The logical progression from a good single roll is to a double (consecutive) roll. Start by pulling the nose up and then commit to holding in the aileron through two complete rolls. Each time the airplane approaches inverted, briefly bump down-elevator (push). As the airplane approaches the start of the second roll, briefly pull up-elevator again (Figure 5). Using the climbing start will make learning when to input the elevator bumps at the appropriate times much easier. When you have mastered the timing of the elevator, you can then easily start to shallow the entry.

While the type of elevator inputs used during rolls are predetermined, i.e., brief bumps, you’ll need to watch the airplane to determine when to input them: “Inverted, upright, inverted, upright.” Remember that the elevator bumps need to be applied individually at the appropriate times. If you go directly from one bump into the next prematurely, you’ll cause the roll to change heading. Keep in mind that you can save hours of practice by taking some time to rehearse on your transmitter and to input individual elevator bumps (in-out) while continuing to hold in the aileron (Figure 6). When you do fly, all you’ll have to concentrate on is when to apply each bump.

ADVANCED UPRIGHT SLOW ROLL

Few maneuvers truly demonstrate pilot skill like the slow roll. You don’t see slow rolls performed by stunt pilots or those who feel equipment upgrades and programming are substitutes for flying skills. The day that you can perform a slow roll the length of the flying field is the day you can truly call yourself a good aerobatic pilot!

After mastering horizontal rolls with timely elevator inputs, you’re ready to start holding in less aileron to slow the roll rate and add rudder during the knife-edge portions of the roll to keep it level. First, keep in mind that it doesn’t matter if the top or bottom of the airplane is facing you; the rudder should always be applied in the “opposite” direction of the roll/aileron input. The rudder is then applied in the “same” direction of the roll entering the final knife-edge. Thus, if you’re rolling right, the opposite left rudder is smoothly applied to maintain altitude through the first knife-edge. Remember to smoothly push down-elevator through inverted and apply right rudder (same direction as the roll) through the final knife-edge (Figure 7). Keep in mind the correlation between the amount of aileron you’re holding in and the pace of the rudder and elevator inputs: The slower the roll rate, the slower you’ll need to apply and take out the rudder and elevator inputs. This is where applying maximum stick tension and paying attention to your control inputs really helps in comparison to merely reacting to the airplane. Be sure to note that the rudder inputs should be just enough to maintain level flight. Visible yaw is not the object; the object is to locate and repeat the control inputs that consistently produce the best results.

The most common error during slow rolls is neglecting some or all of the required elevator inputs and keeping the roll level with larger earlier rudder inputs. Not only can neglecting the elevator result in descents, but applying large rudder inputs before the wings are noticeably banked can also initiate a slight turn. At every skill level, the most influential factor and what dictates the quality and ease of the remainder of the roll, is the roll’s entry. It’s crucial that you input a small amount of up-elevator at the start of the slow roll to prevent it from dropping. You should also delay inputting the rudder until the wings are banked at least 30 to 45 degrees. Don’t forget to smoothly push forward elevator through inverted to keep the plane level before “same” rudder is introduced when approaching the final knife-edge.

BOTTOM LINE

The success of any maneuver, even advanced ones, hinges on good fundamentals. Advancing pilots often assume that any difficulties they run into will require learning more involved techniques or more stick time to solve. In truth, it’s often just the opposite. If you experience difficulties attempting to add refinements to your rolls (or any other maneuver), get reacquainted with the basics and reaffirm the foundation you need to propel yourself beyond the trouble spot. Practice can only make perfect if you maintain a solid foundation on which to build. Happy flying

Text & Illustrations By Dave Scott, 1st US R/C Flight School

The post Flying Precision Rolls appeared first on Model Airplane News.

Begin by flying your plane parallel to the runway about 100 yards away from yourself. When you reach the end of the aerobatic box (1,800 feet wide maximum), pull the plane vertical. If your plane does not head straight up, you didn’t have your wings level. Typically, most fliers hold their inboard wing too low during what looks to them like straight and level flight; when the plane is pulled into a vertical climb, it will start to come in toward the pilot. Continue doing this at various altitudes until you can achieve a vertical pullout. As the plane continues upward, other forces such as prop torque will affect your plane, but you need only concentrate on the initial pull up for this exercise. If you find that you have to apply rudder immediately after you “pull” up-elevator, then you are not flying level. High-wing, mid-wing and low-wing planes will all look different in flight with respect to the ground. Your paint scheme can also “throw off” your perception of your plane’s attitude. Learn what wings-level looks like by practicing it over and over.

Now let’s take the wings-level exercise one step farther: inverted. Yep, throw out your previous sight picture and start again. In an aerobatic sequence, straight and level flight is not limited to upright flight only. In fact, you may spend as much as 30 percent of your flight time inverted while in between maneuvers. You also need to know what inverted wings-level flight looks like. Push down-elevator to enter into a hammerhead at each end of the box, and notice which way the plane immediately leans. Fix the lean angle on the next try with your ailerons immediately before adding the elevator push from straight and level flight. Once the push begins, only rudder should be used. The same thing goes for upright flight. Use the ailerons before the pull, and then use the rudder to correct during and after the pull into the vertical.

Wind correction is another factor that will influence straight and level flight and your vertical lines. (Note: “wind correction” means that you must lean the plane’s heading slightly into the wind to keep the plane’s flight path parallel to the runway and perpendicular to the ground during a vertical climb.) If the plane is crabbed during a vertical entry, it will immediately lean toward the direction of crab. You may need to take some of the crab out of the plane with rudder immediately before the pull. (I emphasized the word “some” to signify that there is no hard-and-fast rule concerning how much to remove.) A certain amount of crab-angle wind correction should be maintained to keep it parallel to the runway. Each plane will act differently depending on its weight, the length of its tail moment and the amount of crosswind velocity. The only way to find how much crab angle you’ll need to remove is by practicing. It may seem simple, but I can’t over-emphasize how important it is to master straight and level flight—for aspiring aerobatic pilots and seasoned veterans, as well. Think of it as the glue that holds your sequence of maneuvers together.

BY DAN WOLANSKI

The post Master the Basics: Straight & Level Flight appeared first on Model Airplane News.

The Sky Wizard comes in for a snowy landing. Note that the tips of the skis are set at a positive angle.

GETTING IN THE MOOD

Dressing warmly is most important for enjoying a day’s flying in the winter. It is even better if you can park your car near your flying spot or find a flying area near a shelter to warm up every so often between flights. A thermos full of hot coffee or soup is a must-have for between-flights enjoyment! If you’re lucky, you’ll find that some winter days can be simply outstanding. With little or no wind, bright sunshine, and milder temps, you won’t even need to wear gloves while preparing your aircraft. For flying, I use a tight-fitting pair of cotton gloves, which allows me to feel my radio’s control sticks. Mechanics’ gloves also work well.

Though I’ve never used them, there are commercial transmitter gloves you can purchase. Similar to Hippo Hands used by motorcyclists, these cold weather radio gloves have a clear panel so you can see your transmitter while your hands are protected from the elements. From my own experience, during the winter months there are many fine days just perfect for flying. The advantage of flying off a lake or a wide open field is that you can always take off directly into the wind, no matter what the direction is. My friends and I have a favorite spot to enjoy cold weather RC flying. Located in the village of Gores Landing, Ontario, Rice Lake is renowned for its fishing in both summer and winter. There’s plenty of room and the scenic panorama is inspiring.

In the winter, I fly my Aeromaster biplane (with floats), and my scratch-designed and built Sky Wizard. The aircraft seen in the pictures is my Sky Wizard, which is an easy-to-fly intermediate to advanced sport plane powered by a Zenoah G-38 gas engine.

The Ace Extreme RC Transmitter Glove is made for very cold flying days. Check them out at acewingcarrier.com.

Here is my scratch-built plywood skis and the limiter cable setup.

The tailwheel ski also uses limiter cables.

EQUIPMENT SETUP

You can find commercially available RC skis online and in hobby shops. Du-Bro has them in a few sizes. I scratch built and designed the skis for my aircraft. I use a tried-and-true method of setting up skis on aircraft that is not unlike that of full-scale aircraft. Check wires and bungees (elastics bands for models) are used to limit the amount of travel the skis have up and down. The elastics are used to keep the tips of the skis in the “up” position, while the check wire at the back limits the amount of distance the ski tips can travel up. The check wires on the front tips of the skis also limit the amount of travel the skis can go down. This is essential to prevent the ski from traveling down so far that it could break through ruts and divots your aircraft might encounter during its takeoff run or landing rollout. It is a very simple and effective way to set up your skis with a minimal amount of funds.

WHAT YOU’LL NEED

• Small eyehook screws
• Elastic bands
• Strong wire (I used pull–pull cable purchased at my local hobby store)
• Short lengths of 1/8-inch diameter copper tubes for crimping the wire ends.
• 1/2-inch, 1/8-inch, and 1/16-inch plywood for upright mounts and ski bottoms. I go a step further and use fishing swivel leads for ease of removal. The skis are built using
• 1/2-inch aircraft ply for the upright mounts and 1/8-inch plywood for the ski bottoms. It is important to have runners on the bottom of the skis to help the aircraft’s tracking. For the tail ski, I use 1/8-inch plywood for the upright and 1/16-inch aircraft ply for the ski bottoms. Another system used to limit the up-down travel of the skis is the torsion rod system or spring system. This is found on Du-Bro and other brands of skis. I prefer my setup described above for its reliability. It has always worked for me.

BOTTOM LINE

I think what I like most about ski flying is the added performance of the aircraft due to the denser cold air. I also enjoy watching the way the skis work during takeoffs and landings. With all the beautiful winter scenery, and the extra time spent with my like-minded friends, there is really nothing better!

10 Easy Steps for Cold Weather Engine Starts

To commit RC aviation, you have to get your engine running. As the weather turns colder, it’s a good time to revisit cold-engine starting techniques. Here are 10 easy steps for flying when the temperature drops.
1. Turn on your transmitter and receiver.
2. Fully open the throttle.
3. Watch for fuel in the line and cover the throttle opening with your finger. Firmly grip the propeller, and rotate it until the fuel is just up to the carb. Don’t flip it! Now turn the prop over—twice, if it’s warmer than 40 degrees F; three times if it’s colder—to prime the engine.
4. With the glow plug disconnected, flip the engine over six to eight times.
5. Close the throttle and move the trim to fully up. This should open the throttle barrel a little more. The throttle should be about one quarter open.
6. Grab the prop firmly, and rotate the engine until it passes through the compression part of the stroke. You should feel the engine kick. If it does, it will now start on the first or second flip. Always use a chicken stick or electric starter for starting. If the engine doesn’t start, flip the prop a few times with the glow plug disconnected, and try again. If it doesn’t kick now, choke it one more time with the throttle fully open, flip the prop a few more times, reposition the throttle, light the glow plug, and try again.
7. If, when your engine starts, it just revs up and quits, turn the high-speed needle valve a half turn counterclockwise to open it, and try again. Repeat this if necessary.
8. If the engine starts, slows down and quits, and if a lot of smoke comes out of the exhaust, turn the high-speed needle valve clockwise to make the mixture leaner, a quarter turn at a time. Restart the engine.
9. When the engine has started, hold the throttle partially open, and let the engine warm up for at least a minute or two before making the final adjustments.
10. Most engines are harder to start when they’re hot. To start a hot engine, draw the fuel up to the carb, but don’t choke or prime it. Open the throttle to one quarter. Flip the prop hard. Use an electric starter, if you have one available.

Getting your engine started in winter isn’t difficult as long as you have fresh batteries in your glow driver and you keep your airplane and engine warm in the car between flights.

Text & photos by Bill McIvor

The post Winter is coming … appeared first on Model Airplane News.