RADIO CONTROL HELICOPTERS
Eric Hawkinson, 319 Yellowstone Ave., Billings MT 59101; E-mail: [email protected]
IT'S ANOTHER great month to be flying Radio Control (RC) helicopters!
For us "up North," I'm writing this at the start of another flying season. That's usually when you see the widest selection of new machines out at the flying field. You also see new faces at the field—nervous novices with questions about everything from gyros to fuel tubing.
It's generally a fun time of the year.
Of course, there may not be many helicopter pilots in your area. I talk to many fellow helinauts who believe they are alone in their quest to master helicopters. Sometimes they really are alone in their area; other times I know of helicopter pilots very near the "solo" pilot's home.
That's one of the drawbacks to helicopters: since no prepared runway is required, people fly them from all sorts of different clearings or fields. If two persons fly at different locations in the same town it may be a long time before either find out about the other.
If you're just starting out with helicopters, it would be well worth the effort to find whatever help may be available locally. Even if it means a few hours' drive, it's a good investment.
Helicopters are complicated devices, and there is much to be gained by sharing experiences.
Finding other pilots
One thing you can do to find like-minded hobbyists is to check with your local hobby shop. Of course, those are getting rarer by the year, and finding one that has any real involvement in niche markets such as RC helicopters has always been difficult.
Still, it won't take more than a trip to the shop to see if anyone else is asking the same questions about helicopters and local activity.
Local airplane clubs can also be fertile ground for helicopter information. There are clubs that have active helicopter pilots as members—some of us fly helicopters and fixed-wings.
Other clubs dislike helicopter activity, but you still might find someone who "knows someone" who flies helicopters.
IRCHA and organized resources
On a broader level, there is AMA's recognized SIG (Special Interest Group) for RC helicopters—the International Radio Controlled Helicopter Association. IRCHA is heavily involved in competition and noncompetitive fly-in events across the US.
Many people seem to think that "IRCHA" is the name of the huge fly-in and event held each fall in Ohio; that's its premier event.
Your $30 annual membership ($35 the first year) in IRCHA allows you to show your support for all the events it helps design and run, and it gets you a bimonthly newsletter, with useful information and many event dates and locations.
IRCHA also has several methods for helping you locate other RC pilots in your area. I think it's a pretty good deal.
To join, send your check along with all your information (address, telephone, AMA number) to: ATTN: IRCHA, Box 3028, Muncie IN 47302-1028.
One thing IRCHA members have done that benefits anyone interested is the Pilot Proficiency Program—a well-thought-out set of "task lists" that range from fairly easy to incredibly difficult.
Each list represents a level, and you gain valuable skills as you master the levels. I think you get the "PPP" list when you join, and it's available from many Web sites. If you prefer to send a self-addressed stamped envelope to me, I'll send you a copy.
Gyros
Lately at my shop we have been flooded with questions about the relatively new heading-hold gyros. Although these types of systems have been available for several years, there is increased rapidity. One reason is the increase in pilots who fly aggressive 3-D style backward, sideways, and pirouetting maneuvers. That sort of flying benefits greatly from the heading-hold gyros.
Another reason is that many of the "regular" pilots are upgrading their older gyros to the new ones.
The big reason is that the newest generation of heading-hold systems are much better in terms of performance and are less expensive than ever before.
Popular gyro models and price ranges
- Telebee 701 Tail Lock gyro: entry-level heading-hold unit selling for less than $100. Made in and distributed from Hong Kong, roughly equal in performance to the old CSM 360. Tends to have some of the same "drift" issues as the 360 and comes with minimal instructions, but is a bargain.
- JR G5000T Extreme Tail Lock: high-end unit with rave reviews, street price approximately $370 (sans servo). JR claims it is far more sensitive and stable than previous gyros. Approved for use only with JR digital servos such as the 8417 or the 8700.
- JR G550T: a smaller sibling to the G5000T, likely to be common at the field with a street price roughly $290. Like the G5000T, it has discrete gain and mode channels and uses a sensor and separate controller box. Unlike the G5000T, the 550 does not require a JR digital servo.
- Futaba GY501 and CSM540: established contenders with much field time. Excellent performers that have largely eliminated temperature-related "drift" of earlier versions. Street price around $220–$260.
There are other units—and probably more new ones by the time you read this—but let's get down to the common questions regarding the difference between standard and heading-hold gyros.
Standard vs. heading-hold gyros
Standard gyros are yaw dampers; they fight to slow your helicopter's rate of yaw, no matter what is causing it—wind, torque, or your thumb on the sticks.
This means that if you set your tail servo to give full mechanical throw on the bench, it will never actually give full throw in flight, because the gyro will be fighting it. (If the gyro has remote adjustable gain, you can use a mix to reduce gyro gain as you input rudder, so the yaw rate can still be maxed out in flight.)
Standard gyros can give very good results when you program in the proper torque-compensation mix in your radio (revo-mix, tail-rotor curves, etc.).
The standard gyro requires little, if any, tail-rotor input when turning in forward flight; the gyro will allow the tail to "weathervane" to follow the turn. (It can't sense rates of rotation that low.)
Heading-hold gyros (they don't have a clue as to what your actual heading is) are much more than yaw-dampers. They are rate-demand systems, somewhat similar to the "fly by wire" controls on modern jets. If you tell the heading-hold gyro to "turn," it will use up to full throw to make the helicopter turn.
If the helicopter is on the ground at the time and thus unable to rotate, the servo will stay at full throw—even after you release the tail-rotor stick—because it's trying to make the helicopter turn.
(It's an old helicopter pilot's tale that the helicopter would then lift off pirouetting unless you centered the servo; when the stick is in neutral, the gyro will again use all of its power and full servo throw to stop the helicopter from rotating.)
The amount of servo travel has little to do with how much you move the stick. The gyro will use whatever amount of throw is required to make the helicopter do what you asked it to do.
Heading-hold gyros do not require—and cannot be used with—any sort of revo-mix or tail-rotor curves.
In forward flight the heading-hold gyros will not allow the tail to "weathervane" in a turn; you have to input tail rotor to coordinate a turn.
Current heading-hold gyros have the option of working in heading-hold or "normal" gyro modes, and they have adjustable gains. The very good ones are able to hold the tail in the desired attitude—even a full-speed tail-first or sideways flight.
All heading-hold gyros do a better job of holding the tail than standard gyros. In most cases, you must use a high-quality (speed and accuracy) servo to get the best results from your heading-hold gyro.
A common area of confusion with the heading-hold gyros has to do with the travel and travel or limit settings. The ATV (Adjustable Travel Volume) settings on the tail-rotor or rudder channel are used to determine the maximum rate of yaw; they are not simply "travel limit" settings. A separate, proportional switched channel named "gain," or actual gyro sensitivity, is used.
Read the instructions carefully, and ask your dealer if you are not clear on how the gyro works.
I'm out of room long before the story is finished. Oh well, I'll be back next month.
Please send photos, questions, or other input.
Happy rotoring! MA
Transcribed from original scans by AI. Minor OCR errors may remain.
