Basic Flight Exercises
Blade mSR and 120SR
Learning to fly a remote control model helicopter requires develop hand-eye coordination and instinctive control stick reflexes. That process is complicated by the physics and aerodynamics of rotary flight which made the model react to stick inputs in ways which a beginner can't anticipate.
Understanding the physics and aerodynamics isn't necessary to learn to fly a model helicopter. Most model helicopter pilots are self-taught by trial and error, often with only a vague clue regarding the underlying cause and effect of how stick movement is translated in to moving the helicopter off the ground, into a hover and across the room or yard. There ways to approach the learning process which are more instructive and less error prone, which with a model helicopter translates into more time flying and less time fixing it.
I've done a lot of process control in my jobs over the years and taught other subjects with as many variables. I always find it is much easier to understand and teach the cause and effect of the various controls if you start with exercises where only one control at a time is changed. If several are moved at once its not often clear which is affecting outcome. Here's a progression of exercises I've found useful for learning and practicing basic flight skills, one control variable at a time, so it's effect can be observed and understood.
In most flying tutorials you will see references to flying "tail-in" or "nose-in". Please erase those terms from your memory banks and instead think of helicopter movement in these terms:
I want to fly it straight
The reason for thinking in those terms are simple and logical:
No matter how the helicopter is oriented to you on ground it will fly in those three directions.
No matter how it is oriented to you on the ground RIGHT movement of either the rudder or aileron will always move the helicopter CW relative to the path it is on.
No matter how it is oriented to you on the ground LEFT movement of either the rudder or aileron will always move the helicopter CCW relative to the path it is on.
Thinking in terms of CW and CCW circles when flying makes it easier to react correctly regardless of how the helicopter is pointing. If flying in a CW circle it goes from tail-in, to sideways, to nose-in, to sideways but it will be in response to right stick inputs. In a CCW circle the orientations change the same way in response to left stick inputs.
On a cause and effect level the direction of the main rotor causes a difference in the way the rudder and cyclic respond. On Blade fixed-pitch models the main rotor turns CW and with the tail rotor thrust also pushing the tail CW to counter the main motor torque (Newton's Third Law of Motion). That causes the models to respond quicker, dive to the right and accellerate when turning CW with the rotor direction and require more input, respond slower, rise and stall when turning CCW. Planning flight paths as a connected series of straight, CW, and CCW legs will help you see and learn to compensate for this trait faster.
Before taking off create a mental flight plan in CW/CWW terms. A figure 8 will either be CW /CWW or CCW/CW depending on starting direction. Simple, No? It may take a few flights to get the hang of thinking in terms of CW/CCW, it should be less disorienting than thinking "nose vs. tail" with opposite stick inputs.
Do you really need training wheels?
Here's another unconventional suggestion: Don't limit performance with lower dual rates for servos and throttle when trying to learn. Here's why. The biggest problem beginners have is OVER-CORRECTING,
The Bell-Hiller hybrid that moves the rotor blade feathering pitch to tilt the rotor is inherently stable and slow to react to Tx stick input. When the stick on the Tx is moved the model will not react immediately and then react more than the beginner expects because, not seeing any immediate reaction, the move the stick more. Then when trying to correct their mistake they over-correct in the opposite direction. That combined with the flybar trying to keep the rotor level with the ground spins the helicopter out of control into a wall. Sound familar?
If your heli is well trimmed and can hold a stable hover I suggest moving to the outer swash balls and using high rate on the 5-in-1 and 100% dual rate and expo if using a Spectrum Tx. That's the level of performance you want to get eventually, and starting without the crutch of the "training wheels" will teach an important lesson: STICK CONTROL. Lower dual rates and expo numb the sticks on the Tx. It's better in the long run to learn to numb the thumbs instead. If you start with the controls dumbed down you'll develop muscle memory of making larger stick movements to affect change in the flight of the heli you will need to unlearn when you increase the responsiveness of the Tx and heli.
When performing an experiment involving many variables the simplest way to see the effect of changing them on the overall result is to first change them one at a time and see what happens. Common sense, no? That's how I suggest you approach learning to fly your Blade model and these exercises, while more boring than zooming around the living room and crashing into things at random, should provide a better understanding of the quirky flight characteristics of the Blade design and helicopters in general.
Take-off and Hover
Hovering a Blade mSR or 120SR is a no-brainer once it is trimmed properly. See the DX6i tutorial for instructions on how to trim for hover and setting throttle curve.
When lifting off spin up the main rotor until it wants to take-off but can't - light on the skids - to the point any rudder stick input moves the tail. At that point the trim should be holding the tail relatively steady.
Push the throttle stick firmly but smoothly to about 70%. Expect the model to jump to the left as it leaves the ground due to the thrust of the tail rotor pushing CW. When it gets about eye level start backing down the throttle to the stick mid-point or where it stops ascending and hovers.
1) Fly a straight line - Elevator only
You might assume a helicopter, once in hover will fly off straight and level by simply moving the right cyclic stick(elevator) forward. The goal of this exercise is to show it doesn't and how much compensation with aileron and rudder will be needed to compensate. Start very slowly, barely moving the stick, without attempting to correct. Then correct and increase speed as you learn to anticipate how it reacts.
From hover move the heli forward and back with just the elevator:
a) facing left
This will teach you how much stick movement is needed to move the heli and introduce you to the pendulum effect of the mSR. Start by moving the heli slowly then gradually increase stick movement as you learn how to control the front/back movement. The left - right orientations will give you a better POV for seeing how big the pendulum swing characteristic of the mSR is when stopping and changing direction, and how much room is needed for the swing, something which isn't as easy to judge if flying tail-in or nose-in.
2) Slide Sideway - Aileron only
The aileron is used different at low and high forward speeds. When a helicopter is moving forward its momentum will put it into a banked curve similar in appearance to an aileron turn of a fixed-wing airplane. But when in hover or moving very slowing moving the cyclic sideways will slide the helicopter sideways.
It's worth noting here that pilots of 1:1 (i.e., full-scale real) helicopters try to avoid hovering when it can be avoided because it puts the helicopter in its most unstable state. One of the biggest potential hazards, especially when taking off is the momentum of rotating rotor flipping it on its side if a skid gets stuck on the ground so they take-off and initiate a forward ascent immediately unless an obstruction prevents it.
The goal of this exercise is to show how aileron adjustment affects position from hover and how response to the same amount of stick movement differs when moving right and left. By just using the aileron you will notice the response is quicker to the right than the left and the model may drift forward and backwards. That is due to the CW rotation of the main rotor the CW thrust of the tail and gyroscopic precession. From hover move the heli with just the aileron:
Start very slow with your stick movements and do not move the rudder or elevator in this exercise. The point of the exercise is to change just one variable, the aileron input, so you can see and understand how it affects the orientation of the heli both in the intended way, moving it sideways, and unintended ways such as yawing of the tail.
3) Slide Sideway - With rudder correction
In a real helicopter flying with the nose forward is a basic requirement because the pilot needs to see where the heck he's going. But with a model your POV is external allowing it to be flown in any orientation to get from point A to point B. In exercise #2 with just the aileron you may have deviation in direct caused by yawing of the tail. In this exercise you take the control skill learn in #2 and combine it with controlling the rudder at the same time to keep the sideways flight exactly 90° from the orientation of the nose. First practice this:
a) tail-in moving left and right
Then once you get the hang of keeping the body of the helicopter in-line with rudder cx try it:
a) facing right heading away from you then coming back towards you
Repeat the exercise with the nose pointing in the opposite direction. Opposite aileron input will be needed to move it away and towards you.
When flying sideways away and toward you the front / back movement of the heli can be compensated for by changing the sideways angle. For example, if when flying sideways towards you nose facing right the heli starts to deviate to the right, adjust the rudder so the tail moves CW slightly and the heli will fly to more to the left. In sideways flight the aileron acts like the elevator does in tail- / nose-in FF and the rudder cx correct the flight path.
Don't worry about the angle of the body of the heli relative to the desired line of flight, watch the main shaft and adjust the controls to keep it moving along the desired path from point A to point B.
4) Box Pattern - With 90° rudder turns
Using the skills / reflexes acquired in exercises 1-3, fly a box pattern, flying the heli straight and level, coming to a controlled stop at the corner then turning the heli 90° with rudder input to fly the next leg of the box. Practice this flying forward CW and CCW around the box pattern. Then if you are up to the challenge try doing it backwards, tail-first. You may want to go back to exercise #1 and fly straight lines backwards first. When you can complete the pattern with equal length legs and no directional miscues move to the next exercise.
5) X Pattern - Diagonals across the box
Similar to the box exercise, but when you get to the corner of the box turn the heli only 45° with the rudder and fly sideways across the box in an X pattern to the opposite corner. Practice this starting from each of the four corners.
6) Round Circle using Rudder - CW and CCW circles
This exercise teaches how to smoothly coordinate elevator to keep the helicopter moving forward, rudder to steer it around the circle, and throttle to keep it at the same altitude. Note that the goal here is to NOT use the aileron initially, so the rotor's natural tendency to tilt (differently) during CW and CCW will be seen. After trying to fly wide circle of equal radius a few times with just the rudder/elevator/throttle add aileron as needed to keep the rotor level as the helicopter negotiates the circle. You may find it easier to start out with the already learned box pattern then gradually round off the corners until you achieve a perfect circle over one spot in front of you.
All of the above exercises can be done in a small space if you start slow and limit stick movements. As your hand / eye coordination improves and you come to understand how the heli reacts you'll be able to increase speed of the heli which performing these basic exercises. Depending on your temperament and preferred learning style you may (or may not) find it helpful to take notes and try to come up with some memory aid to help you remember what stick inputs create which direction of travel when nose- and tail-in.
The following are exercises are recommended for when you have more room to practice and fly:
1) 180° Flip Turn
In this exercise the goal is learning to change direction 180° to avoid a crash into a wall and the pendulum effect that occurs when trying to stop abruptly. The learning curve for this exercise is understanding how much room the mSR needs to stop and pitch up then using that stall to rapidly change direction 180° by flipping the tail around and flying back into open space.
a) In nose down FF pull the elevator back to get the nose up, then increase throttle to arrest the forward progress. Inertia will keep it moving forward while lift from rotor tries to stop it, it will pitch nose-up in an arc then stall as the forces of forward inertia, lift from the rotor, and gravity equalize
b) At the highest point of the arc where forward progress stops, make a 180° turn of the tail with a quick rudder input so the nose is now pointing down. Try this spinning the tail around CW and CCW. You will find that spinning the tail around CCW decreases tail rotor thrust and there will be a lag getting it spinning again and stopping 180° later. CW tail movement increases tail rotor thrust making it easier to stop the spin and fly back out in the desired direction.
c) Apply forward elevator and throttle and fly out of the induced stall in the opposite direction.
The heli, while light in weight, still must obey Newton's laws of motion, so the faster its moving the more room is needed to stop it and reverse the direction. But it is also a maneuver where the faster the heli is moving forward and the more quickly and aggressively the pilot moves the sticks the better it works and the less space it takes to do. With practice you can fly full bore in one direction, stop in mid-air, then pivot and zoom off at full bore in the opposite direction; all in the comfort of your 10 x 10 foot living room. It's all just a matter of timing and letting the forces of gravity and lift do most of the work.
2) Banked Aileron Turns
Here the goal is to learn how to turn the mSR in the same way a car, plane or real helicopter negotiates around a sweeping banked curve. You'll want a lot of space to practice this: in a gym or outdoors on a calm day.
RC Model flying seems to focus on how fast and radically the orientation of the heli can be changed and flying upside down, but real helicopters are flown more like an airplane most of the time they are in the air, upright using smooth coordinated banked aileron turns similar to those an airplane makes. But executing a simple banked turn also requires thinking about the effect of control inputs in "3D". Once in the bank the elevator, which in level flight pulls the nose up or down will affect the radius of the turn. Because the rotor is tilted it will initially stall as it is banked against the forward momentum requiring a coordinated manipulation of elevator and throttle to keep it moving around the banked curve in the sky at the same altitude.
As with a car the steeper the banking the faster the tighter the curve can be negotiated. Without any banking a car in a curve requires a lot of steering input to change direction of the car and too much speed will cause the car run off the road or the heli to blow out of the turn. As banking is increased tighter radius turns can be made faster with less steering input (relative to center) is required. The same is true of a helicopter. In a banked turn moving the rudder stick the rudder points the nose up towards the outside or down towards the center. That would be important in seeing where you are going if sitting in the pilot seat, but less so steering from the ground so when doing the exercise pay the most attention to the tilt of the rotor, elevation and speed and in most cases the gyro will keep the nose in line with the forward momentum.
In an airplane or collective-pitch model the roll is induced by moving the aileron in the desired direction of the turn then, but once the wing / rotor is at the desired banking angle the cyclic stick is returned to the centered neutral position. To cancel the turn the process is reversed with a momentary opposite aileron input to move the wing / rotor back level with the ground. The 45° flybar stabilized FP mSR and 120SR operate differently. On Blade FP models moving the aileron stick will cause the rotor to tilt, but if the stick were released and re-centered as with a CP model the 45° flybar will start to try to self stabilize the rotor and after some violent out of control pendulum swinging will eventually settle down into level "hands-off" hover attitude. So unlike the airplane or CP heli its necessary to continue to apply aileron and elevator input during a sweeping banked turn.
The learning curve you'll climb practicing aileron turns is discovering how much aileron and rudder input is needed for various degrees of speed and turning radius and coordinating the two. At first you'll want to practice wide sweeping turns in a large space like a gym or outdoors in calm air where there is plenty of room. As you get more coordinated and increase the amount of aileron input and speed you'll be able to execute tighter radius banked curves and move the practice indoors, but with more speed comes more risk of damage when you mess up.
Some Parting Thoughts on How to Steer
Now when I fly I find myself totally focusing the the model and the attitude of the rotor which predicts where its heading and tuning out the background completely except to look towards where I want it to go next. That's something I learned from commuting on motorcycles for many years (over 100,000 miles) is that if you see something in the road and fixate on it more often than not you will hit it! That occurs because the brain is accustomed to steering towards the target your eyed are focusing on. So instead train yourself to look where you want the model to go next and you will find that your reflexes, honed with these exercises, will send it there.
Once your skills are developed to the point where you can do all these exercises without needing to mentally plan ann the steps you will find models going where you will them to go. That's when the flying really gets to be fun!