Getting Into 3D Heli Flight- Your First Flips and Rolls
Posted on December 16, 2009 by aaronredbaron
3D helicopters are experiencing tremendous growth, in a large part because of advancements in technology, and the availability of lower priced helicopters capable of aerobatics. With many new people coming into the hobby there are more and more outstanding pilots all over the world. Becoming proficient at advanced aerobatics can seem daunting, but finding your comfort zone during the first steps into aerobatic flight is usually a bigger hurdle. Taking the time to learn the basics before you get ahead of yourself, and having a well rounded concept of what you are doing and how you will go about it before trying anything new will help prevent trouble.
One reason advanced aerobatics are actually easier to learn is by that point you should have already mastered how to recover from any attitude or orientation, which is precisely what you have to learn as you take your first steps into 3D flight. Without an understanding of how the controls will respond, many beginners get in trouble when they begin to panic. Over-control can bog (over-load) the rotor head, reducing control and stability. Further over-control in an attempt to recover can make the situation worse as the rotor’s RPM continues to decay.
One or the other; not too much of both
Collective and cyclic pitch make the helicopter respond differently, but both function through the management of the pitch angle of the blade. More pitch on the blade takes more power to move it through the air, putting more load on the drive train. When you demand excessive pitch, the additional load on your rotor head slows it, and as the RPMs decay, the stability and control are reduced with it. This is why you need to avoid using both full collective and full cyclic inputs at the same time during your flight, regardless of the attitude or maneuver you’re trying to pull off. It helps to remember what each control is for; cyclic pitch inputs tip the disk, and collective pitch inputs give the helicopter lift upright or inverted.
A classic example of a simple maneuver which can go horribly wrong if you use too much input would be a vertical down-line, such as during the last portion of a loop. To recover from the helicopter diving straight at the ground (vertical down-line), over-control of both collective and cyclic will result in the helicopter simply loosing head-speed and struggling to pull out, and the helicopter will likely drive itself straight in. The correct inputs would be to maintain the collective close to zero and apply back cyclic to cause the helicopter to pull out of the dive. As the helicopter rounds out the bottom of the recovery, you would let off the cyclic input and apply collective pitch to maintain level flight. Understanding this concept will help as you get into aerobatics and will become second nature as you become more proficient. Although its commonly referred to as “collective management”, perhaps a more appropriate name of the skill would be “pitch management”, because your ability to manage the relationship between the collective and cyclic pitch directly affects how your helicopter will fly.
Getting It Upside Down and Back Upright the First Time
Before you attempt your first flips and rolls you should be comfortable with hovering your helicopter in all orientations, and you should be able to fly forward flight with ease. If you have a simulator, its an excellent tool to attempt new maneuvers and find your comfort zone before you commit to trying it in real life. If you have an instructor who can help you on a buddy box, take advantage of the opportunity. Before you try any aerobatics, be sure your gyro is holding your tail solid, and do not attempt to piro the helicopter during the maneuver, or if you have to recover. When you pirouette your heli the orientation is constantly changing, so its best to leave the tail alone and focus on getting your helicopter leveled out first. Regardless of whether you try it on the simulator first or in real life, here are some simple steps to follow to flip or roll your helicopter. Start in a high hover in Idle-Up mode with the tail in the position you are most comfortable with, for most people that would be tail-in, or the helicopter facing away from you.
- Pick a direction- Whether you want to flip or roll, pick a direction, stick with it and follow through the same way untill you are back upright. Flipping forward away from yourself is recommended because you are likely to go further away from yourself instead of closer if you encounter a problem. For the sake of this example, I’ll use a forward flip.
- Begin the maneuver with a mild climb-out.
- Ease off the collective so its as close to half stick (zero pitch) as possible, and at the same time apply the cyclic input, in the case of this example, forward cyclic.
- Hold forward cyclic as the helicopter flips to inverted, and as the helicopter nears inverted, ease off the cyclic and bring the collective down to apply negative pitch. Apply enough negative pitch to get the helicopter to climb inverted.
- Ease off the negative pitch by bringing the collective back to half stick, and apply forward cyclic again.
- Hold forward cyclic until the helicopter is back upright, and then ease off the cyclic and apply positive collective again to maintain flight.
These steps all happen in smooth succession, and they need to be instinctive. The helicopter will follow your commands to a T, which can be a detriment when you panic and begin to chase for control with too much input. If you panic, keep the collective close to zero, and continue to hold forward cyclic until it comes back upright. As long as you begin high enough (a few mistakes high, as some might say) you should have no problem getting the helicopter back upright without loosing too much altitude. Those first flips are likely to make you feel like your stomach is in your throat, or the “pucker factor” is in effect, if you will. Once you get the first flips under your belt, you will begin to feel much more comfortable about the entire process. With practice, you too can be throwing your helicopter around like a pro, but you have to get through those first few before the feel of it will begin to really sink in.
