Safety Comes First
Gary A. Shaw
As I write this column it's early November. The daily temperatures have started to drop, and the trees are starting to take on an autumn-like appearance here in Florida. I guess I should thank hurricanes Erin and Opal for leaving a few behind. With the cooler air and a howling wind (courtesy of a passing cold front) it seems only appropriate to grab a cup of coffee and head out to the workshop to catch up on some projects that have been unfinished since last winter.
Normally the number-one item on my list of things to do after an active flying season is a thorough safety check of my flight box. I say normally because I was gone so much that I really didn't have a flying season. While I was contemplating just how thorough the check should be (I'm naturally lazy), a copy of the Transmitter arrived from the Belleville RC Flyers of Mascoutah, Illinois. It contained a thorough checklist, written by modeler Ray Telican. Since Ray covered the subject rather nicely, I've included his list.
- 12-Volt Starting Battery: Does it have any loose or frayed wires? Does the positive terminal have an insulator over it? This wouldn't be the first time someone shorted a battery out and started a fire, with disastrous results. Are the terminals clean and free of corrosion? If you carry your transmitter in the same box as the battery, be aware this subjects the transmitter to the same corrosion. It could make for some interesting flights next spring! If you carry your 12-volt battery in the same box as your fuel can, is it at the other end of the box? A small spark near the fuel can in warm weather could cause a rather unpleasant explosion.
- Starter: Are its wires free of kinks and frays? Are the alligator clips (or banana plugs) securely attached? Does the switch on the starter stick in the on position? Maybe this would be a good time to have it repaired. If the rubber prop/spinner adapter flies out when the starter is engaged, consider replacing it.
- Electric Fuel Pump: Does it have good connections? Does it leak? If so, replace or repair it. Remember, fuel leaks could start a fire.
- Power Panel: Check all the electrical connections. Make sure they're clean and secure. Some panels use a dropping resistor for 1.5-volt glow-plug voltage. This resistor gets very hot and needs ventilation. Is yours getting enough air? (Columnist's note — If the electrical connections on the back of the power panel weren't sealed by the manufacturer, use a hot glue gun and coat all bare wires and terminals. All it takes is a touch from a loose wrench on the back of an exposed panel to spark a fire or explosion.)
- Glow Plug Battery Leads: Are the connections at both ends good and tight? If you use alligator clips, make one wire shorter than the other so the clips can't touch. On a headlock-type connector, use the plastic cap provided by the manufacturer when it's not in use so that nothing can short it out.
- Transmitter: If you don't fly during the winter, charge the batteries at least once a month. This would also be an excellent time to run a capacity check.
- Transmitter Antenna: Is it straight, free of broken sections, and clean? (Columnist's note — Try a little WD-40. Spray it on a rag, extend the antenna, and wipe it down.) Does it have the proper frequency numbers and tags attached? Also, do you have the proper frequency markers for use on the frequency control board? If not, this would be an excellent time to make them.
- Props: Check them for nicks, cracks, dinged ends, and proper balance. Maybe you left one in the box that should be disposed of. All of the nylon-fiberglass types should have the sharp edges sanded off. One of our most experienced club members had to have eleven stitches put in his fingertip a few years ago when he slipped up the backside of a fiberglass prop.
It Started On Its Own
Such is a story passed on to me by modeler Jim Halls of Johnston, Vermont. He revealed that his Saito FA-130TD engine (with an onboard glow ignition system) started without being actively flipped.
While at the flying field this past September, Jim and his helper finished priming the Saito according to the manufacturer's specifications, which require flooding one cylinder. He had attached glow drivers to two of the four plugs on the engine. Jim's helper was holding the 1/4-scale Cub by the tail.
Jim was distracted for a few seconds — then to his surprise, the engine suddenly started on its own! Thankfully, Jim's helper was holding the tail, the engine was at idle, and no body parts were located near the prop.
Jim attributes the start to a hydraulic lock that may have occurred during priming, as well as an onboard glow system that lights up when under compression.
Food for thought for those of you who think it's safe to start a "big bird" by yourself. The next time you're at the field, remember Jim's experience and always have someone hold the airplane and/or make sure it's tightly secured to a pole before proceeding.
On a similar note, in the past I've received correspondence indicating that small engines have similar faults when they're loaded up with aerosol after-run oils. Apparently the propellants used in some spray cans have a tendency to ignite under compression. This sometimes results in a blubbery run for a few seconds. It could be enough to damage unsuspecting hands, so be careful the next time you flip over an engine — you never can tell!
A Near Miss
From the hallowed pages of the Cascade Model Helicopter Club's newsletter Heli-Views comes a story by Bill Vosburgh. Bill describes a hot affair between a battery and a fuel can. To learn about what not to do when transporting fuel and electric equipment back and forth to the flying field, read the following:
"At the end of a flying day, an RC aviator was loading his vehicle with flying gear. Two other club members that were performing similar chores finished first and departed, leaving our man to complete his final duties. These consisted of picking up his battery box, fuel can, and folding chair.
"The flier picked up his battery box in one hand and the metal fuel can in the other. Anxious to avoid one more trip, he decided to carry the battery box and fuel can in one hand and the chair in the other hand as he headed to the vehicle. No sooner had he transferred the hardware, when the exposed battery terminals shorted against the can — it immediately exploded, blowing the top off the fuel can. Fortunately, the top separated first (on the side away from the victim), which directed the blast away from his hand, arm, and body. The can fell to the ground, tipped over, and ignited the grass. The flier was very fortunate to have avoided being seriously burned — just a sore shoulder from the kick of the explosion."
Need I say that the individual somehow dodged a silver bullet? Glad to know this story ended with a somewhat happy ending (although bruises are still nothing to be thankful for). Be careful, folks! Don't forget that methanol and electricity were only intended to meet during the compression stroke inside a model engine!
In March 1995 I received a letter that contained several stories written for use in a local newsletter. As I was looking through the stack in preparation for this month's column, it became clear that the following piece made a point that would end the column nicely.
I Learned About Flying From That
"It was one of those days when nothing seemed to go right. There was some wind—a few gusts now and then—but not enough that I could blame my rotten flying on it. I guess you could define it as an RC flier's equivalent of a 'bad hair day.' Landings just wouldn't go right. I would either bounce because I was coming in too fast, or bounce because I stalled a foot or so off the ground. Then I would either be too long and barely stop before the weeds, or come in short and have to apply power to reach the field.
"After one of those short landings when I barely made it to the runway, the airplane ground-looped and ended up over on the flightline side (at the west end of the runway) with the engine still idling. I couldn't taxi it back because the wheels were stuck in a rut or something, so I had to walk down to get it.
"When I got there I pulled the fuel line off the carb and shut the fuel valve off. I tied the plane down with the tail up and left the engine running to burn the fuel out of the lines. I started back to the pits and, after a few minutes, returned to find the plane smoldering. The glow fuel had soaked into the grass and the muffler was glowing red and setting the grass on fire. The tail had burned clean through.
"Once I had the airplane freed from being stuck, I turned it around and started to taxi it back to the flightline. I realized then that I had the whole field ahead to take off from, so I thought I would just go ahead and take off—once the airplane was in the air, I would walk back to my pad while flying the airplane.
"So I taxied out to the runway, lined up, and applied full power. Then I lost directional control of my airplane! There was only one other person on the flightline, concentrating on flying his airplane, but my airplane was heading right toward him and it took me a second or so to figure out what to do to miss him.
"Meanwhile (as the result of yells and screams from other club members) he did a marvelous job of toe-dancing to keep out of the way of my wayward airplane. I finally got the model under control and in the air, but had to fly around the pattern for a few minutes to calm myself down enough to land the airplane in one piece.
"What did I learn about flying from that? The first thing I learned was not to fly from a place on the field where things did not look familiar. The field looks entirely different from the end of the runway!
"The second thing I learned was, when things start going ape, immediately cut the power and try again after calming down. Don't try to save a takeoff that starts going bad!
"The third thing I learned was when you are having a bad day, just clean up the airplane, load it in your car, and enjoy watching the other guys fly—or have a nice, social chit-chat with those who aren't flying!"
Until next month, enjoy the building season, and keep the glue off your fingers!
Transcribed from original scans by AI. Minor OCR errors may remain.
