Altitude Limited Old-Timer (ALOT) is the term for the Society of Antique Modelers’ (SAM) version of the popular Altitude Limited Electric Soaring (ALES) event for AMA electric sailplanes. It was first mentioned in my column in the December 2012 issue of Model Aviation.
The SAM version has been tested in a few contests, including the 2013 SAM Champs, but the event got off to a rocky start because of several small problems.
Contest organizers settled on the Winged Shadow Systems Sky Limit device as the most suitable for the event, but after a number of the units were purchased and used, the device permanently dropped off the market.
The Competition Altimeter for Models (CAM) unit, which is used in the Sailplane event, is less versatile but is useable for electric-powered models, with some minor modifications to the trial rules. Fortunately, there are alternative units available.
Last year’s SAM European Championship was successfully run using mostly European-made altitude-limiting units. In the US, we’ve been testing HobbyKing’s altitude-limiting device, which appears to satisfy most requirements. We encountered a possible problem with one installed in a spark ignition ship, requiring further testing.
The Winged Shadow Systems Sky Limit units can still be used for all fuel- or electric-powered aircraft, and the CAM units can be used for electric motors or glow engines that can be controlled by throttle.
The HobbyKing instruction booklet is slightly difficult to interpret, but I’ve decoded it into a simpler “cheat sheet” for ALOT use. I can supply a copy to anyone interested who sends an email or a self-addressed stamped envelope.
The ALOT event differs from electric ALES in that it allows any and all SAM-eligible airplanes to be flown, regardless of power source, as long as power can be shut off by radio control. It’s expected to be flown at the upcoming Bolder City SAM Champs, held October 19-23, 2015, in Nevada. It’s strictly a fun gathering and will not replace any basic SAM events.
By shutting power off at a preset low altitude, we hope the event attracts some fliers who are either intimidated by the high power requirements of many SAM RC events, or whose eyesight isn’t fit for steering models at high altitudes. The event will also allow the use of some interesting old engines that are otherwise not competitive in regular events.
SAM Rule Book
The 2015 SAM rule book is available for $5, and it’s recommended that you get one if you join SAM and/or especially if you plan to compete. SAM rules are complex, but that’s because of the large number of events. The book will remain in effect for five years until the next rules-change cycle.
On the topic of rules, Gene Wallock posted some interesting off-the-wall AMA rules history on the SAMTalk Forum message board. One of the items is worth repeating. Here’s the story as alleged:
“Frank Ehling was responsible for some of the early [National Aeronautics Association] NAA model airplane rules. Frank entered a contest and when his turn to fly came up he walked out to the launch circle with his timer and a shoebox. Frank said he was ready and removed the lid.
“A pigeon flew out and Frank told the timer to keep it in sight as long as he could. Needless to say, the [contest director] CD was not amused, but Frank pointed out that there was no rules reference as to who built the model, and Frank opted for God.
“The Builder of the Model rule was born.”
A Little CL History
Early Control Line (CL) models were often flown clockwise. This made sense at the time because just as it is today, most engines ran counterclockwise as viewed from the front. Propeller torque rotated the aircraft properly to counteract the weight of the control lines. Later, as inverted flight developed, the advantage became a disadvantage when flying inverted.
In the late 1940s, flight direction shifted to counterclockwise, although several aircraft had been designed for clockwise flight. There was another advantage to counterclockwise rotation: right-handed pilots had more visibility of the flight path ahead, especially if an unforeseen obstacle, such as a stray moose, should wander into the flight path.
Today, you can guess the era when an older model was built by which side the control lines exit.
I recall dedicated Free Flight (FF) pilots criticizing CL flying and saying it was similar to flying bricks on strings. At first, most of us flew overweight, overpowered airplanes with small wings because that was what the industry could produce in compact boxes at a low cost, while still making a decent profit. Before Stunt flying was perfected, speedy, racy-looking little models were the “in thing.”
Although most CL designs would never have made it as FF fliers, a CL aircraft didn’t have to be bricks kept in the air by brute power and centrifugal force. It took modelers such as George Aldrich, Davey Slagle, and others to show the rest of us that larger, lighter models could execute smoother, more realistic maneuvers while being more fun and easier to fly.
Our local CL club members slowly began flying RC, and only when I was one of the few left standing in the circle, did I move over to RC.
Today there is little, if any, CL flying in my town, partly because of a lack of a flying field. I miss CL because life seemed much simpler then. You simply hand started an engine and flew. Using a good fuel filter, the only adjustment needed was one click of the needle valve in the spring and another in the fall. Mechanical failures were rare and unless you flew Combat, an airplane lasted forever.
Contest modelers want to build lightweight models. Because construction consists mainly of wood and glue, those are two of the chief items that the builder can control. One piece of advice frequently given to novices is to concentrate on minimizing glue weight. Make closely fitted joints and only use the necessary amount of glue.
Your control of balsa weight is limited to what you can purchase. Balsa density is usually expressed as pounds per cubic foot. It’s a term familiar to FF modelers and anyone else who is concerned with keeping weight to a minimum. Another common term is contest-grade balsa, with “gold standard” wood being as light as 5 pounds per cubic foot. Most balsa is roughly double that density.
There’s an old formula for quickly calculating the weight of balsa into pounds per cubic foot. Using standard 3-inch-wide by 36-inch-long balsa sheets, make a stack of them that is 1 inch high. Weigh the stack on an accurate scale. The weight in ounces is also the weight in pounds per cubic foot.
This trick works because a volume of 1 x 3 x 36 inches happens to be 1/16 of a cubic foot, and an ounce is 1/16 of a pound. You can tinker with the arithmetic for final proof.