Safety Comes First!
By John Preston
Frequency Control at the RC Flying Field
Jefco Aeromodelers — Chatfield Aerodrome
More on RC frequency control. In last month's column there was a discussion of how to control the use of RC frequency channels at the flying field. A letter recently received from Paul Samaras, Safety Officer for Jefco Aeromodelers of Lakewood, CO, describes the system they use to prevent frequency conflicts. First, a few words about the Jefco Aeromodelers flying field—Chatfield Aerodrome.
An adjoining photograph shows an aerial view of this outstanding field. It was formally opened in October 1978 after four years of hard work by the members, who were successful in negotiations with parks and recreation department officials and state and federal agencies in obtaining 50% of the financing from these outside sources. A 25-year contract between the club and the state ensured that their investment in both time and money was well spent. At the time the field was opened, the club had about 100 members, so the expense to the club of some $10,000 worked out to about $100 per member. Even taking into consideration the value of the dollar in 1978 compared to today, this was a small price to pay for such an outstanding flying site.
Aside from the excellence of their facilities, perhaps the major difference in operating procedure at Chatfield Aerodrome versus your average RC club is the requirement that you "pit by color." According to Paul: the pits are broken down into seven areas, each 10 x 20 ft., and each has its own transmitter impound that holds 10 transmitters. There is a pole off the right side of each impound with three transmitter pegs on each impound board available for all to see. It is in the rules that when you come onto the field your transmitter goes on the board in the area of the pit that you are flying out of. It is also in the rules that, before you place your pin on the pole, you inspect every transmitter on your board to see that they are turned off. If you don't do this, you really deserve to be shot down by someone who could have forgotten to turn off his transmitter.
Surprisingly, they have constant reports at meetings from people who, when checking all transmitters, occasionally find one left on — about once a month. Now consider those transmitters left on in the pits at clubs that don't have this fine system where you can't look at everyone's transmitter to be sure. I'd venture to say that most so‑called receiver problems are not receiver failures but are the result of those who forgot to turn off their transmitter in the pits when they're done flying.
As you no doubt have already concluded, the Jefco club uses the "Additive" frequency control system (see last month's column), where each member has his or her own frequency pin and adds it to the control board before turning on a transmitter. They now have almost 200 members, and Paul says that their system can handle upwards of 70 planes a day very smoothly. To handle the 11 new RC channels, they are erecting a second pole on each transmitter impound board that will have pegs for the new channels, divided among the existing seven pit areas. In eight years time, when the total number of available channels jumps to 50, the Jefco Aeromodelers plan to extend the length of the pit area and add more transmitter impounds. As you can see in the accompanying photograph, their existing pit area is as big as the runway of some RC clubs I've visited. It must be nice to have all that space to play with.
RC Flight Training
Charleston Radio Control Society — Training Guide
Another interesting letter came from Ken Guilford, a member of the Charleston (SC) Radio Control Society. Ken responded to the request in the March Safety column for information on clubs' flight training programs. Since Ken's letter was the only one received in response, I assume there aren't many clubs with a formal training program for beginners. The following information on the Charleston club's training program could help your club get started and might reduce the number of models a beginner goes through before becoming proficient.
Ken wrote: "Enclosed, find a copy of our Training Guide. We have 15 instructor pilots in the club and find that this system works pretty well. It is hard, sometimes, to get a pilot (student) and an instructor together, but if the student keeps at it he will, by law of averages, get in enough flying time to enable him to become proficient. Our instructors try to have the student do certain things each lesson. The student is required to provide his own airplane and radio equipment. We have found that it helps to use the same airplane all the time. We also find that it helps a lot if the student is able to get one of the club's trainers for the first sessions. Each student is permitted to fly a club trainer for only two practice sessions until he shows enough progress to be given solo time. The student is not permitted to solo until he proves that he can take off, land and fly a rectangular pattern consistently."
Their club has about 90 fliers, and only about seven are not qualified.
Along with the letter, Ken sent their Training Guide booklet that contains the Trainee Lesson Plan together with the club's Field Rules. The lesson plan consists of 12 individual steps that start with an inspection of the plane and equipment and finish with a qualification flight. Each step has a description of what must be performed and is followed by a space for the signature of the instructor and the date on which the step was accomplished. The 12 individual steps are:
- Plane & Equipment.
- Test Flight & Trim.
- Familiarize Trainee with the Equipment.
- Perform Circles with No Altitude Loss.
- Perform Figure Eight with No Altitude Loss.
- Straight Flight Over Field at Altitude.
- Square Pattern Flight.
- Make Takeoff.
- Make Landing.
- Observe Solo Flight.
- Perform Maneuvers: Loop, Roll, Immelmann, Split-S.
- Qualify.
Step 12 — Qualify, states: "The qualification flight should take place with at least one instructor and one qualified pilot as observers, and the maneuvers requested by the qualifier need not be specific but rather should be what will demonstrate the student's ability to fly alone and safely."
The Training Guide booklet also has notes for both the instructor and the student. An important note to the instructor states: "One more thing. Remember that the trainee is probably a newcomer and has not yet achieved building proficiency comparable to yourself. Do not criticize his building. If the airplane is sound and the equipment is installed properly, save your comments for a later date." Amen!
I've often heard derogatory statements made by self‑styled club experts about the building prowess of beginners. Wrinkles in the Monokote are hardly likely to result in an unsafe model, especially if the covering is applied over sheet balsa. Ridicule of the trainee is hardly likely to inspire confidence, so would‑be instructors should learn to praise that which is good and only correct visibly bad things that bear on the airworthiness of the model.
One addition that could be made to the Charleston club's Training Guide is advice on choosing a model for the beginner. Ken noted that new members often join the club with a model already constructed. Those who contact the club prior to purchasing their first model are invited to the field to observe equipment and models being flown, and they are directed to a local hobby shop run by a modeler for recommendations. Ken wrote: "We don't push a particular model or brand of equipment but it is hard not to do, as there are some excellent trainers that cannot be avoided in any discussion." What they try to recommend is a trainer that will stand up to hard use and be easy to fly: a high‑wing monoplane with tricycle landing gear and a flat‑bottomed airfoil with dihedral is a good choice.
Urethane Foam — Do Not Hot‑Wire
Before signing off for this month, I received a letter from MA's Associate Editor (he’s the guy that censors—see editor's note below) about a model supply catalog offering foam boards. The catalog warned: "Do not hot‑wire urethane foam, as a hazardous gas is discharged." He said he wasn't aware of this and asked how to tell urethane foam from other types such as polystyrene.
First, the hazardous gas. What is it? Among other things, the fumes from burning urethane can contain hydrogen cyanide. Not the best thing to be breathing if you desire to continue modeling to a ripe old age. If you dig out newspaper reports of the hotel fires of a few years ago (in Las Vegas and New York), you'll find that most victims were "overcome by fumes" from the burning building rather than being burned themselves.
For the most part, those fumes are produced by burning urethane foam. You don't have to be a model builder to have urethane foam in your home—check the stuffing in your sofa, pillows, mattress, etc. Chances are it's urethane. You don't have to fear for your life should these items catch fire, because the foam produces such dense smoke when it burns that your smoke detectors will trigger long before you become endangered. (You do all have at least one of these, I'm sure! If not, pass up that next gallon of glow fuel you were going to use to burn holes in the sky and instead buy a smoke detector so your own home doesn't burn some holes in you.)
Lastly, how do you tell urethane foam from polystyrene? I'm not sure I can answer that fully right now. Chances are that if a brand name is present on the product, it will also state what the material is. In case you are wondering, "foamie" models are not urethane. I will look into this further and report back in a later column.
Meanwhile, go out and buy yourself a smoke detector. Eight bucks is cheap life insurance. Have a safe month.
(Editor's note: I do not censor John's columns — I merely help to perfect them! RMcM.)
Contact
John Preston 7012 Elvira Ct. Falls Church, VA 22042
Transcribed from original scans by AI. Minor OCR errors may remain.
