Safety Comes First!

SAFETY COMES FIRST!

By John Preston (Safety tips contributed by Ed Farabaugh)

RC helicopter fliers—present or potential—are urged to give careful consideration to the following material. Life and limb are involved.

RC helicopters have some unique characteristics: they can be flown almost anywhere, even in close quarters, when the skill of the pilot permits. They can be flown slowly—even at zero airspeed. These characteristics may make a helicopter appear relatively safe. If we ignore the speed and mass of the rotor system, a hovering machine doesn't look particularly dangerous. If we disregard the possibility, however remote, of mechanical or electronic failure—or the possibility of the pilot being distracted or tripping while concentrating on the machine—the danger becomes obvious. A spectator who approaches a hovering machine may startle the pilot and cause a mishap.

With these characteristics and the inherent dangers of RC helicopters in mind, the following guidelines are presented.

1. Don't fly alone. Smart swimmers don't swim alone. Your helper doesn't have to be a pilot, but he should know how to control spectators and how to drive or phone for help in case of an accident.

1. Don't start the engine until all machine screws have been secured with Loctite (or equivalent) or with locknuts.

1. Don't attempt to fly until you have thoroughly checked the radio system and all mechanical linkages, especially after a less-than-soft touchdown.

1. Periodically check all clevises and ball-and-socket connectors. These are subject to wear; if not replaced when necessary, they can come apart while the machine is flying.

1. Get to know your carburetor. Don't fly more than a few feet off the ground until the engine is up to operating temperature (about 4–5 minutes). The idle and low-speed mixture adjustments are important—even beyond the half-throttle position. The carburetor may go lean and you won't have enough power to get the machine down safely.

1. Don't trim your machine by lifting off while holding the tail. It looks easy, but the tail rotor can nick your knuckles and the main blades can remove a section of your arm; reflexes could knock the machine out of control. With care, adverse trim characteristics can be detected just before or just after liftoff from a safe distance. If the machine isn't right, set it down for correction.

1. When new components are installed in the rotor system, anchor the machine securely to the ground so it can't lift off. Lower the pitch a degree or two and run the machine up to a higher-than-normal rpm for a few minutes. Do not stand near the helicopter during this test. Maintain a distance of at least 75 feet. Strict spectator control is a must.

1. If blade axles or strap-type blade mounts have been bent during a mishap, discard them. Even if you can straighten them perfectly, they have been fatigued and might fail in flight.

1. If the helicopter vibrates noticeably at any time, don't continue to fly. If there is a sudden change in vibration level, land immediately and check it out. If everything is secure, lift off carefully to check tip tracking. If tracking is correct and the machine still vibrates, shut it down and inspect blade balance, the shaft, engine mount, and control linkages. Vibration can destroy a radio system; a slightly bent shaft can "go wild" at flying speed and may destroy more than the helicopter.

1. Pay close attention to battery maintenance. Helicopters use more flight-pack energy than airplanes. Four or five servos running most of the time can empty a battery quickly. Find someone who understands batteries to teach you proper maintenance.

1. Helicopters attract children and dogs. Don't start the engine without proper crowd control. Designate a safe location from which spectators can observe and tell them not to wander while the machine is off the ground. Explain that you can't keep track of their movements while concentrating on flying. Don't fly when there are children on bicycles in the area—they may not be able to get out of the way if the machine goes out of control.

1. Don't fly close to buildings when it's windy. Adverse air currents can knock your machine out of control.

1. Stay away from telephone poles and wires. They can cause big trouble.

1. If you fly in a metropolitan area, be aware of possible radio interference. Someone may inadvertently be on your frequency, or another RC operator may be nearby. Make it a point to find out if others are operating in your area. If you don't fly at a club site, find out where local club fields are and don't fly closer than five miles to any RC field. It's not your private frequency—your receiver may be confused by another transmitter!

1. Listen to your helicopter. If you hear a strange sound, your machine may be trying to tell you something.

1. If you notice a glitch, set the machine down and turn off the receiver or the engine until you determine the cause. If you suspect a radio problem while flying, get it down and kill the engine or the receiver quickly. If the battery voltage drops below critical, the engine could go to full throttle.

Radio Trouble Shooting

If you notice abnormal servo movement during flight, there are many possible causes:

1. Someone may be on your frequency. With the engine off and the receiver on, momentarily turn off your transmitter to see if the receiver is picking up stray signals.

1. You may have metal-to-metal-generated radio noise. Search the entire machine for a loose bolt or something allowing metal to rub on metal with the engine running—pay special attention to the landing gear and attachment points. Do not use metal clevises on the metal throttle lever.

1. Your transmitter radiation may be marginal because of low voltage or other causes. With the engine off, range-check the system with the antenna partially collapsed.

1. You may have to run the engine at various speeds to find the problem. Anchor the machine securely (as in guideline 7), start the engine and run it up to speed. Watch for abnormal servo movement while moving the controls slowly through all positions. You may be suffering from dirty servo potentiometers, dirty or broken wires or connectors, a broken antenna, or a bad solder joint in the receiver switch.

1. Static electricity generated by the tail rotor blades can cause problems. If you're not sure, try running a ground wire with a mounting lug to the positive terminal of the battery.

1. Your antenna may be picking up reflections from other components. If you have a metal tail boom and the antenna runs parallel to it, try allowing the antenna to hang straight down from the front of the machine. If this corrects the symptom, reroute the antenna as far from the rest of the radio system as possible. Do not coil the antenna inside the machine—radio range can fail beyond 10–15 feet.

1. A new model or a new radio receiver may be too sensitive. In some cases you may need to ask the manufacturer's factory to desensitize the receiver slightly.

1. If you can't find the cause of a radio problem, contact a radio expert or someone with extensive helicopter-related radio experience.

Model helicopters can be dangerous, but most problems occur when they're under the control—or lack of it—of an inexperienced pilot or ground crew. Careful attention to detail during regular maintenance and flight operations will reduce risk.

Postscript: A word of warning to fliers of ducted-fan–powered models. We recently learned of a modeler who is now missing two joints from his middle finger after contact with the fan while adjusting the engine needle valve. Be extremely careful during this type of operation or, better still, consider adding an extension to the needle valve so it can be adjusted from the exterior of the model.

Experience is a wonderful thing—it enables you to recognize a mistake when you make it again. (Seen by Pat Wickert on a sugar package at Sky-Nauts annual banquet.) While we might agree, we'd rather you didn't make the mistake in the first place.

See you next month.

John Preston 7012 Elvira Court Falls Church, VA 22042

Transcribed from original scans by AI. Minor OCR errors may remain.