The 2009 SAM Champs
Bob Angell | [email protected]
The 2009 SAM (Society of Antique Modelers) championships were flown in September on the dry lake in Boulder City, Nevada. The site offers almost unlimited, unobstructed space for free-flight (FF) models and a flat surface for safely following them on a chase bike. Radio-control (RC) competitors enjoy a spacious landing area, which they are required to land inside to complete a score.
We enjoyed mild weather all week except for Tuesday, when the wind blew all day and few flights were made. The events scheduled for that day were moved to Wednesday or Thursday.
Social activities and schedule
It can be a busy week if one attends all of the social affairs associated with the contest. There's barely enough time after flying to clean up and get to the events, which typically include:
- Monday evening: collectors' swap meet, concours judging and voting, and engine raffle
- Tuesday: bean feed
- Wednesday: SAM membership meeting
- Friday: banquet and ceremonies
The meet headquarters was the Fiesta Henderson Casino Hotel, which is well equipped with meeting rooms and banquet facilities. Perhaps fortunately, our modeling-related social activities didn't leave much time for us to transfer our life savings to the casino.
Model of the Year
Each year, a Model of the Year is chosen for special recognition and awards. The entire line of Comet Model Company designs was honored for 2009. The highest-scoring Comet model in any of several preselected events received an extra award. Nancy Kapitanoff was a guest speaker and presented her documentary film about the Comet Model Company; she is a descendant of a man who was active in the company. The film included many scenes from early model meets that had hundreds of fliers and spectators in attendance.
The flying activities are the highlight of the SAM Champs, but many people attend solely for the opportunity to socialize and reminisce with those who produced the history we're re-creating. The flying events are too numerous to list here, but a complete set of contest results, including aircraft flown, is available on the SAM website.
The SAM Champs alternates every other year between the Nevada site and the AMA National Flying Site in Muncie, Indiana. The 2010 Muncie event will take place September 13–17. Featured Models of the Year are the Kerswap for power and the Gollywock for rubber. Both are simple, built-up balsa constructions, with plans and/or kits readily available through resources listed on the SAM website.
Flight-covering tip: undercambered wings
"Undercamber" describes the concave shape on the bottom surface of some airfoils. It's common on older aircraft from the Wright Brothers era through roughly World War II. Here is a construction tip for covering an undercambered wing with iron-on film. It's well known by many old-timers but may be new to those working with these shapes for the first time.
Covering steps:
- Seal the covering only around the outer edges first, so the wing initially looks flat.
- Apply a thin coat of dope or other adhesive that soaks into the bottom rib edges to improve adhesion—smooth rib edges help the film bond.
- Make sure the wing is vented with escape holes to prevent trapped air.
- Begin sealing the wing bottom by using a small, wetted soft cloth to closely follow the tip of the sealing iron, pressing the covering against each rib as you move from the leading edge (LE) to the trailing edge (TE).
- During this operation, you will pull the iron tip toward you rather than pushing. Move slowly to keep the covering pressed in place until the cloth cools and sets the adhesive.
- Rather than working progressively from one end to the other, begin with a rib in the center of the span and then continue dividing the remaining area in halves. This minimizes distortion.
- Shrink any wrinkles in the open areas using the iron with a very light touch while avoiding reheating the ribs. A heat gun is not recommended here.
Additional tips:
- Use light-colored covering if the model may be exposed to heat, as dark films absorb more heat.
- Ventilation and good adhesion at rib edges are critical to long-term stability.
The Playboy Jr. incident
The aerodynamics of undercamber are complex, and a recent experience at the SAM Champs added practical insight. On the second flight of my 1/2A Texaco Playboy Jr., the model was basically out of control during both the power run and the glide, porpoising badly (alternately stalling and recovering). I was fighting it with elevator the whole time, and gentle rudder inputs for directional control made things worse. The model made a reasonable landing, considering the conditions.
I inspected for loose items, checked controls by cycling them while applying light pressure to the surfaces, and performed a radio range check. Finding nothing obvious, I elected to fly again. On the next flight the model was even less controllable and wandered into a strong thermal while still under power. The thermal carried it higher and downwind as I lost the struggle to keep it in the field.
A closer inspection after recovery revealed that the undercamber covering had released across the whole center section of the wing. That's slightly embarrassing after offering the adhesion tips above. The only thing I hadn't done was apply sealant to the bottom rib edges before covering. Contributing factors were the plane's age (probably 20 years with hundreds of flights) and the use of black film on the bottom center section, which is more prone to heat absorption. Occasional storage in a warm, closed vehicle likely promoted loss of adhesion. The wing had been vented to prevent pressure buildup.
So what happened? Apparently a model that is properly trimmed with undercamber becomes severely tail-heavy if the undercamber is suddenly released. With the covering loose, the airfoil bottom may change shape during the continuous stalling ups and downs. If any aerodynamicists can verify or expand on this, comments would be appreciated.
Heroes and Hall of Fame
Every sport, hobby, or art form has its heroes—those who excel and inspire others. Aviation and model aviation have many such figures. The AMA, SAM, the National Free Flight Society, and other SIGs maintain halls of fame. SAM inducts new hall of fame members as part of the banquet that concludes SAM Champs week.
When I lived in Bremerton, Washington, two local heroes were Henry "Hank" Cole and Chuck Hollinger. Our model club consisted mostly of high-school teens struggling to master flying techniques. Hank and Chuck were accomplished "older" modelers who owned a hobby shop across Puget Sound in Seattle; we had read their names in magazines associated with contest wins and model designs.
I had met them fleetingly once in the late 1940s at a local contest. The club was enthusiastic for weeks after learning Hank and Chuck were coming to our meet. They performed a fine demonstration and won several events. I corresponded briefly with Chuck before he passed away a few years ago.
Then, at the 2009 SAM Champs bean feed, a man sat down beside me and introduced himself as Hank Cole. What a nice surprise after approximately 60 years! We had the kind of dinner conversation and experience one hopes for during the event. Later in the week I learned that Hank was being inducted into the Model Aviation Hall of Fame during our banquet ceremonies.
Electrified Valkyrie
George Shacklett of Knoxville, Tennessee, sent photos and a description of his newly completed and flown electric-powered Valkyrie. He is shown in his backyard, but behind him is a city-owned and -maintained field where he can fly. We should all be so lucky.
George believes his is probably the first full-size Valkyrie to be electrified, and he also has a Forster .99 engine–powered Valkyrie he built earlier. Being practical, George uses the same wing for both models—most of us would become practical in a hurry before constructing two such wings.
Sources
- SAM (Society of Antique Modelers)
- www.antiquemodeler.org
Transcribed from original scans by AI. Minor OCR errors may remain.
