Letters to the Editor
Air Cadet: Setting the record straight
As pointed out by several readers responding to my Air Cadet construction article in the February 1992 issue: yes, it does indeed bear a resemblance to the old Comet Models Gull design.
The Air Cadet's design was influenced by the Cessna Bird Dog (L-19 — Ed.) and the Comet Gull, with both aircraft sharing some similar design attributes. The model was called Air Cadet to reflect the color scheme and military markings. Similarly, the Cessna Bird Dog saw action in Korea and Vietnam.
It was a great oversight on my part for not mentioning the Gull in the article. I apologize to Comet Models and the Model Aviation readership for the mistake.
David Fortuna Evington, Virginia
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Nothing but praise!
In the January 1992 issue of Model Aviation, page 111 in the "Product Review" section, you can see custom-bent wire landing gear.
I am very impressed. The gear I bought was custom-sized to the plane I was building. The price was reasonable, the delivery prompt, and the gear was excellent. It's near to perfection as you will ever see. Each time I examine it I admire it more.
After several years of bending my own wire gear, I really do appreciate it. I highly recommend it to everyone. Buy it — you'll like it.
Bob Marston Sebago Lake, Maine
Bob Shattleroe Custom Gear, take note!
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Youth full-scale soaring scholarship
May 31, 1992 — entry deadline. "Soaring Flight" essay contest, ages 14–22. $500 in sailplane lessons, first prize. Entry forms are available at any U.S. soaring site. Get a list of sites from Soaring Society of America, P.O. Box E, Hobbs, NM 88241; tel. (505) 392-1177.
John H. Campbell Scholarship Director, Collegiate Soaring Association (AMA member)
OK, folks. If you're interested, there's still time to enter this essay contest. Anyone interested in flying may apply if they are between the ages of 14 and 22 and are not already an FAA-licensed pilot. The forms are only available at U.S. soaring sites! Don't write to Model Aviation or AMA Headquarters for entry forms or information! — RMcM
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Errant propellers: A couple of cures
A propeller and nut spinning off the engine shaft is not an uncommon occurrence. A possible solution to this problem is to make the shaft with left-hand threads with the corresponding nuts. This would counter the direction of prop rotation and tend to tighten the nut instead of loosening it during engine operation. This could also apply to prop screws in .049 engines and might be considered for future engine-shaft design.
A solution to the existing problem is the use of self-locking (stop) nuts (which I presently use). Some of these nuts have nylon or fiber inserts; others are all-metal types with distorted threads to provide the locking action.
In some applications there is not enough room on the prop shaft forward of the prop to accommodate a regular-size stop nut. There is available, however, a low-profile nut.
Military designations for these stop nuts are:
- MS 20365 — Self-Locking Nut, Plain
- MS 20364 — Self-Locking Shear Nut (low-profile)
The same types of nuts are available in hardware stores, boat stores, and aircraft supply houses.
Arthur J. Distasi Salem City (NJ) RC Club Delaware City (PA) RC Club Chester City (PA) RC Club Glen Mills, Pennsylvania
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Does anyone know Construct-A-Plane?
While visiting my brother recently, I reminded him of an airplane kit our dad brought back from a trip to New York in 1935. He was surprised that I remembered and said, yes, he had kept it, never built it, but carried it around whenever he moved, intending some day to build it. The kit, a model of an Albatros D-5A, is in perfect condition. It has a 24-inch wingspan and was designed and drawn by Stephen Graffeo. The plan is dated 1934. The model is a "Gold Seal Kit" from Construct-A-Plane, Inc., located in Brooklyn, New York.
The plans are highly detailed, even showing a control stick and rudder pedals with cables and pulleys to operate the control surfaces. In addition to the balsa sticks, print wood, hardware, and two colors of silkspan (green and yellow), the kit contained turned hardwood wheels and a machine-cut balsa propeller.
My question is this: does anyone have any knowledge as to the background of this 57-year-old kit, its manufacturer, and the designer? Is there any historical interest in this type of model product?
John Kok 7633 Ampere Ave. North Hollywood, CA 91520
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Is there new Electric technology?
Why have we not heard much about new developments in electric power which might benefit aeromodelers—lithium batteries and new electric motors, for example?
If lithium batteries give four times the endurance of Ni-Cads, would we not be on the cusp of the perfect power, capable of equaling glow engines in power, weight, and endurance, with some special advantages:
- Reliability, cleanliness, lower noise, simplicity.
- Constant torque at all rpm — the great boon that would permit standardization of model parameters and scale multiblade propellers at low rpm.
I believe the electrical industry can now supply us with motors, servos, batteries, and receivers light enough for indoor RC. In the meantime, congratulations to the inventor of the MCC (MCC = migrating combustion chamber — Ed.) engine — but will its producers set up with a modern all-electronic ignition and down to 1/2A size? As a small aero model enthusiast I am tired of cranky glow engines spewing oil over my pretty models.
Perhaps it is time for AMA to look beyond the aeromodel industry and to ask the wider world of industry to produce what we consider desirable. As long as there are no new initiatives from outside, model aero manufacturers will continue to sell us the same old glow bangers.
Anthony French New York, New York
We turned to our resident Electrics guru, Bob Kopski, for help in answering the questions raised here. Bob had this to say:
"There seems to be a growing variety of lithium cell types/technologies available on the market. These cells generally offer 'higher energy density'; i.e., a lot of energy storage in a relatively small and light container as compared with the more commonplace Ni-Cd and lead/acid types. There are even some rechargeable versions of lithium cells. These properties make them sound attractive for Electrics.
"However, as far as I know, lithium battery technology is still rather expensive (try buying a lithium battery for your new, high-tech 35mm camera!), and while breakthroughs occur frequently, the latest information I'm familiar with is that the high discharge rates now commonplace in our Electrics (20 amps or more) are still a 'no-no' with lithium—at least at any reasonable price.
"In general it's been my observation in life that until a given technology reaches the consumer level, it's probably not affordable for most modeling applications—even assuming that it's suitable in the first place. This means that, for example, until you see rechargeable lithium (or any other battery technology) routinely showing up in relatively high-current consumer items—like battery-operated power tools, video cameras, etc.—you're not likely to see it in Electrics! Let's look forward to the time!"
— Bob Kopski
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Bellanca vs. Lindbergh's Ryan: A question about efficiency
I recently saw the movie The Spirit of St. Louis with Jimmy Stewart as Charles Lindbergh.
Lindbergh's Ryan was a custom-designed monoplane which was delivered at a cost of only $17,000. It is difficult to imagine what the price for the same custom-designed plane would be today!
It is interesting to note that Lindbergh originally wanted to purchase a Bellanca monoplane, but the manufacturers wanted the pilot of their choice to fly it.
Lindbergh then went to a lot of trouble to cooperate with the designers of the Ryan to make the plane as light as possible for one man and no passenger. A lot of effort was given to eliminating even the most minor of items.
But then Chamberlain (as pilot) and Levine as owner-passenger flew a Bellanca monoplane farther than New York–Berlin with no huge gas tank up front and not so much concern for weight.
My question is, can anyone give an idea of what went into the Bellanca that made it so efficient? I believe it was about the same size and used the same nine-cylinder Wright Whirlwind engine.
Karl Valasek AMA 79085 3922 Lawn Ave. Western Springs, IL 60558
P.S. With a little more gas Lindbergh could have made it to Berlin, but I guess that with so much absence of sleep it was lucky he got as far as he did. But that was his goal: Paris. — KV
OK, all you experts. How about it? — RMcM
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Hear! Hear!
I have been reading the Safety column in Model Aviation for several years. I don't know if you have ever addressed the issue of hearing loss associated with model airplane engines.
I have been around model airplanes of all types and sizes since I was about eight years old. I was diagnosed as having a high-frequency hearing loss at age 12. This loss of hearing has been traced to model airplane engines.
The club that I currently fly with requires that engines not exceed 90 dB at nine feet. Ninety decibels at that distance can cause damage to ears in a very small amount of time. Even engines with mufflers still emit a substantial amount of noise that can adversely affect our hearing.
The advice that I would like to pass on to everybody is to practice what I do: wear hearing protection while in the vicinity of or while you are operating a model airplane engine. I try to make hearing protection just as important as staying out of rotating propellers.
If you have addressed this item in the past, I am sorry I missed it. Hopefully you can provide a refresher for all of the new people in our hobby.
Scott Kordes Cheyenne, Wyoming
Your Publisher also suffers from this same type of hearing loss — and more than likely due to the same reason. Although I knew of the possibility of suffering hearing loss due to this cause, I just knew it would never happen to me. Hah! — RMcM
Transcribed from original scans by AI. Minor OCR errors may remain.
