Radio Technique
INSTRUCTOR PILOT. The mechanics of RC flying are quite simple. The student pilot must learn to see what the airplane is doing, and believe. A certain amount of eye-hand coordination must be developed. The student also needs to understand some principles of aerodynamics and kinematics in order to be able to predict what the machine will do. What must the instructor pilot do? The most important thing he must do is build up the student's confidence. He has other tasks as well, which we will discuss below. One of the photos shows John Kleisler with an ST .29-powered biplane which he has designed and built. John's father, Philip, has been my friend for over 20 years. During most of that time, Phil has concentrated on designing, building, and flying RC Sailplanes.
Radio Technique
A LITTLE GAME for your club meeting. First, I'd better give you some reference information: As of December 20, 1987, the FCC (Federal Communications Commission) mandates that we abandon 72.08, 72.16, 72.24, 72.32, 72.40, 72.96 and 75.640 MHz. During 1987 you will either convert your old wideband AM (OWB-AM) sets to one of the existing even-numbered, high-bandwidth channels (RC38-RC56), or you will junk them. The game we're going to play can help you make the decision. Note: You will not convert those old RC systems to the new 1988 low band channels. As of January 1, 1988 the AMA will sanction even-numbered RC channels from RC12 through RC58, less RC36. As I explained last month, it is intended that only narrow-band equipment will be used in the low (RC12-RC34) channels. There is no restriction against using narrow-band equipment in the high band (RC38-RC58), also-in fact we recommend that you do it.
Radio Technique
INTERFERENCE-FREE GROUP. I've spent most of the month of September sitting at my computer working on programs to solve Frequency Committee problems. I'm not its chairman any longer (Fred Marks is), but I maintain an active position as a member of the committee as well as being the District II Frequency Coordinator. As a fallout of the above effort and of responding to requests from my friend Norm Rosenstock as well as from Jim Sears (AMA VP for District VI), both of whom asked for "a list of frequencies, all of which can be operated at the same time without interfering with one another," I offer the following:
Radio Technique
HOW FAST is it turning? This month's subject is tachometers. The first one I remember using was called a Vibra-Tach. It looked like a small X-Acto knife, but a piece of music wire extended from the end where we usually see a blade. To use the tool you rested it on the engine and slid a ring which encircled the handle back and forth until the free end of the music wire took up a large oscillation. The body or "handle" was engraved with an rpm scale, and you read the step nearest the position where the ring had to be to let the wire show the wide vibration. It worked on the principle of resonance. When the mass, length, and stiffness of the wire combined to show the wide vibration, the free part of the wire was in resonance with the engine. There were several difficulties with this instrument, among them being finding access to a cowled engine and the unavoidable effects of prop wash.
Simple Structural Test Techniques for RC Aircraft
SO FAR AS I KNOW, there is no college course in test engineering, and this column is not intended to serve in its place. An approach at that level would have too many pre- and co-requisites in terms of mathematical skills, physics, chemistry, geometry, economics, law, drafting standards, machine shop practices, and so on. In this series I will concentrate on structural test techniques for RC models, with digressions into related subjects when I think it is necessary, keeping the mathematics simple. This is the first digression.
