Safety Comes First
Gary A. Shaw
Box 4520, Milton FL 32572; E-mail: [email protected]
It's hard to believe the holidays are just around the corner! It seems like yesterday that Y2K was the major issue in the news, and that the end of the world might be near. I'm glad that prediction flopped!
It feels as though I just took the Christmas lights off the house, and now it's time to put them up again! Not many things in life are more enjoyable than decorating the house with the kids, other than maybe flying a charged model in clear, calm skies.
Look at the bright side: if it's too cold to fly outside, you have the time to write a Christmas list! You could start with one of the new short antennas, or some gloves to keep your hands warm during those long winter flights.
I need to correct a comment I made in the September 2000 Model Aviation. I stated that I use WD-40™ to clean my antenna on a regular basis.
I have had a number of problems since then that have led me to replace a telescopic antenna with a short, flexible unit. The substances in the WD-40™ eliminated the antenna's ability to broadcast a reliable signal.
To clean an antenna without causing the above problem, rubbing alcohol is an effective choice; it doesn't leave residue to gum up contacts on telescoping parts. Give it a try and let me know the results.
Range-checking and antenna security
I've received many letters about the methods you can use to range-check your transmitters for good signals prior to flying.
Range-checking is an important part of flying Radio Control (RC). It tells you the likelihood of the antenna not working before you launch a model.
There is nothing worse than the helpless feeling of watching your pride and joy take off, then plow into the ground—ouch! Ralph Swank (Tampa FL) has a similar warning.
"The conclusion of your column in the September 2000 Model Aviation reminded me of an incident I had several years ago.
"I took my Senior Telemaster off without doing a range check. It responded normally until it was about 200 yards away. It stopped responding to the transmitter, and continued to climb at full throttle, then began a gentle bank. It continued to bank until it was diving, and then it crashed into a (Ford) Taurus, between the windshield and hood, at the landfill where we flew.
"[The model] was about a half-mile away, but I heard the crash clearly. So did the lady driving the car. What my homeowner's insurance did not pick up, the AMA insurance did.
"The post-mortem revealed that the wire from the radio works to the antenna, inside the transmitter, had broken. There was enough signal transmitted to get it off the ground. The wire broke because there was play between the transmitter box and the antenna, allowing the antenna to twist, and eventually break the fine wire from the radio to the antenna.
"Still another reason to do routine range checks, and to determine that the antenna is sound and secure."
From the Mailbag: propeller safety
I've written about the dangers of propellers, and I have included questions about safety concerns using current propeller technology.
The original question posed to me was, why does AMA allow the use of the current variety of propellers (carbon fiber, glass-filled, plastic), but not the use of metal propellers? As described by the individual who asked the question, the types of propellers mentioned damage flesh just as bad—or worse—than the metal propellers that have been banned.
The answer is that metals don't stress well, and tend to break without warning. They can also cut you severely, but I'm told that wasn't the main factor for having them banned. The issue is weight and kinetic energy when metal breaks and a piece goes flying.
Carbon fiber breaks, as does wood and glass, but there's much less energy—and potential injury—to worry about.
Although I love the performance of the new stuff, I prefer wood propellers because I know they will give way to things that contact them, rather than plowing through.
The following is Ken McClenahan's opinion:
"On the subject of metal propellers (in your column in the August issue of Model Aviation), they were prohibited when I first joined the AMA in 1956. I, too, have my qualms about some of the plastic propellers. The types available in the 1950s were not much worse than wood, but the modern fiber-filled types are probably as dangerous as metal.
"The problem is that the evolution from the original frangible plastic types (e.g., Scamper, if my memory of brand names is correct in going back over 45 years), through nylon, to the modern types, was gradual so we (as a group) kept accepting each new type, even though it would not have been accepted as a step change from the first type.
"We seem to have a general problem with not adjusting rules to fit current technology. As an example, using wings with foam leading edges on Control Line Combat models violates the spirit of the rule prohibiting sharp or sticky leading edges, but with so many contestants using wings with foam leading edges, how can I as CD [Contest Director] prohibit them?
"Incidentally, one of the avowed advantages of using foam wings is that foam leading edges will snag streamer leaders (and they do just that)."
Battery and connector cautions
Chris Hushak (Sterling VA) warns of a potential problem with battery connections in transmitters that use push-in type battery technology.
"I own a few radios with similar setups, so his letter caught my attention. If you have similar radios, you might try his solution to the problem. I have, and now I fly worry-free.
"This past weekend, I took a Zagi hand-launch flying wing out for its first real start launch, using a Hitec three-channel AM (Amplitude Modulation) radio. At the top of the launch, the airplane went into a hard right bank, followed by a 200-foot vertical dive. I had no control.
"At the crash site, I checked out the controls and all appeared okay. After a complete range check and several hand tosses, I tried the hi-start again (gotta love EPP [expanded polypropylene] airplanes). This time, the flight was uneventful until within 50 feet of ground. Again, I had no control and the airplane spiraled in. Again, I checked the controls. Not working. Hmmmm ...
"I took the airplane back to my workspace and tried the controls again. Again nothing. This time, I noticed the green LED (light-emitting diode) on the transmitter wasn't on. It's hard to tell on and off in bright sun. I'd prefer if all manufacturers use meters or digital readouts.
"The Hitec three-channel radio version I have uses an eight-cell battery holder with a nine-volt battery connector at the contact end. This makes a push-fit connection to two copper tabs within the radio itself. Sure enough, the LED would come on, depending on how I wiggled the transmitter.
"I took the whole mess home, opened up the transmitter, soldered a nine-volt battery clip with leads I had in my junk box to the copper clips, and snapped the connector to the battery tray. This took care of the intermittent transmitter problems.
"My guess is that I lost the transmitter power at the top of the first hi-start launch. The long walk to the crash site restored contact for the subsequent range check and hand glides. Then, the extra motion of the next flight broke the contact again.
"Note: I am using Ni-Cds in place of dry cells in the transmitter (and receiver). The charger jack requires a Futaba-type charger and plug to convert an otherwise fine RC system to full Ni-Cd operation."
That's it for this month. I hope you have a wonderful holiday season and a happy new year!
Until next month! MA
Transcribed from original scans by AI. Minor OCR errors may remain.
