Radio Control Helicopters
Mark Fadely [[email protected]]
Gary Wright talks about electric helicopters
HELLO! I’m glad that you’re bravely entering the helicopter arena this month. You have to love the extended helicopter coverage you are seeing in MA.
Pilots often ask, “When are we going to see more helicopters in the magazine?” That time is now! The emphasis can’t always be skewed toward the rotary world, but it is nice when we get extra exposure.
I’ll dive in with more information from the IRCHA (International Radio Controlled Helicopter Association) Jamboree: the crown-jewel event for the wigged-out helicopter lovers. You’ll have to read about it in this issue’s feature article, but let’s delve a bit deeper into some of the information gathered there.
There were a ton of electric-powered helicopters at this year’s Jamboree. The electric side of the hobby has had its struggles and growing pains throughout 2009. Batteries and speed controls have been expensive and sometimes not all that reliable. Manufacturers have taken notice, resulting in the production of much better, less expensive products.
Also included in this column:
- How to do pirouetting flips
I was pleasantly surprised to see my friend Gary Wright at the event this year. He is a pioneer in RC electric development. Gary is one of the most knowledgeable people in the hobby, and he was a fine competition 3-D pilot. He was up there with Curtis Youngblood during the last decade.
Gary was kind enough to answer a few questions I thought our readers would be interested in knowing the answers to.
MF: Gary, there are so many more electric helicopters in the marketplace today. What changes have you seen in motors, electronics, and batteries over the years?
GW: Batteries are the only things that have changed significantly. Electric motors and speed controls have gotten better, but it has been incremental.
Lithium-Polymer batteries with high discharge rates have changed RC electric flight. A lot more power is available from a much lighter pack. The old Nickel-Metal hydride batteries were really heavy.
One thing a lot of pilots don’t realize is that they may not even need the expensive high-C Li-Poly packs. If you are going to fly over six minutes, then the lower, less costly packs will work just fine.
MF: So if you are not flying radical 3-D, then you are probably better off with the cheaper batteries?
GW: That’s right. Most pilots would really benefit by getting longer flights for more training time, and they would be saving money at the same time. One big difference between electric vs. nitro power is that the high-discharge batteries can be drained very quickly. That is the biggest difference today. You can essentially drain the electric “fuel tank” in four minutes. If you could burn all of your nitro fuel in a 90-size heli in four minutes, then you could have the same power as the electrics.
MF: What size helicopter would you recommend for a pilot who wanted to learn and progress with total electric power?
GW: They don’t really rate electric helis the same as nitro. Electrics are referred to by battery size. A new pilot could get a six-cell heli that could be set up to provide good flying power for 15 minutes. That is a real luxury to have that kind of flight time and not have to worry about tuning needles on a nitro machine.
I would recommend a beginner pilot get a 500-size model, and after he is ready then he might move on to a 600 or 700.
Thanks for sharing that good information, Gary. You have been an inspiration to so many pilots through the years.
Pirouetting Flips
I can't tell you how many times I have been asked how to do a "piro flip." The proper name of the trick is a pirouetting flip.
Most aerobatic helicopters are capable of performing the maneuver. It does not demand a great deal of power or aggressive capabilities from the machine.
Many months ago, the subject was covered in this column. This time I thought you all would appreciate a visual representation of the maneuver while I write about it.
I fired up the RealFlight simulator, and stick-stirring ensued. As do many complicated maneuvers, the piro flip seems easy to do after you have it mastered. However, it might seem impossible during the early learning stages.
The best recommendation is to keep trying this complicated move on a simulator until your thumbs are numb. There is no substitute for practice.
The piro flip is like no other maneuver, and it involves a sophisticated control-input sequence. Many times, a pilot will begin to do the move using timing and a basic knowledge of the required stick inputs.
That is a dangerous way to try it on a real machine. If your timing is a bit off, the model could end up in an attitude that is completely foreign to the pilot, which might result in a crash.
As with all maneuvers, the piro flip can be broken down into segments that can be learned as small parts of the full maneuver. Basic control inputs on a Mode 2 transmitter are to stir the right (cyclic) stick while the left stick (rudder) is deflected and held to perform a constant yaw rotation.
While these control inputs are being executed, the helicopter will flip while the tail is spinning. Then the pilot needs to coordinate the positive and negative collective to maintain a constant altitude.
The rotation of the cyclic stick has to match the rotation of the model at all times, or the maneuver will go awry. Synchronizing the cyclic is the most troublesome thing to master.
Pilots often ask, "Should I watch the nose or the tail to stay in sync?" It doesn't matter which end of the helicopter you key in on, as long as you remain consistent. Once you input a few wrong stick positions, the machine will be heading out of control in a hurry.
In the simulator image, you can see that there is a limited amount of stick inputs during the maneuver. That usually surprises pilots.
When you watch a piro flip being performed, it seems like a lot of control must be required. It is actually the opposite. The images of the helicopter have been spread out so you can see the orientations better.
In a real-world example of the move, the model should stay in the same space and perform the flip around itself, with no altitude or horizontal position changes. The maneuver shown is a two-piro version, meaning that there is one pirouette during the first half flip and another full pirouette during the second half flip. The helicopter ends in the same orientation as it started.
When I learned the trick, I did the one-pirouette type, which has only one pirouette during the whole flip. That version of the maneuver requires much more cyclic input and loads the helicopter much harder. The two- or three-pirouette-per-flip variations are much more elegant and pretty to watch.
I hope the illustration will help some of the readers understand the nuances of this difficult and exciting move. Don't be afraid to ask other pilots for help when you are attempting to learn something.
That is it for this time. I hope you'll be back for more RC helicopters next month.
Sources
- IRCHA — www.ircha.org
- RealFlight — www.realflight.com
Transcribed from original scans by AI. Minor OCR errors may remain.
