Free Flight Sport - 2010/03 | Model Aviation Library

Author: Gene Smith

Edition: Model Aviation - 2010/03
Page Numbers: 118,119,120

Free Flight Sport - 2010/03

Author

Gene Smith <[email protected]>

FF Nats event name change

The NATS STARDUSTER event has had a name change. It is now called the "One Design Combo" to more accurately reflect its intent.

You can fly any of the former One Design event 1/2A Gas models in the class.
If the airplane is early Nostalgia or Nostalgia-legal, it must be flown with a Nostalgia-legal engine.
All other designs can use a Nostalgia-legal engine or a TD .049 or .051.

Lincoln Beachey monoplane — Paul Grabski

Paul Grabski built a Lincoln Beachey monoplane for the Slow race at the 2009 Flying Aces Club (FAC) Nats at Geneseo, New York. As the event's name implies, the challenge is to fly a course as slowly as possible.

Paul's model is based on Walt Mooney's plans for a 16-inch wingspan Beachey. He made several changes to make it closer to scale and easier to fly: changed the wing and rudder outlines and the wing airfoil, shortened and corrected the fuselage shape and the cowl outline, and enlarged the wingspan to 21 inches.

The color scheme is based on an eyewitness account in the book Lincoln Beachey: The Man Who Owned the Sky, by Frank Marrero. The airplane was described as yellow and silver. The name "Beachey" on the wing is shown in a photo in the book.

Paul is using a wobbly rear peg that acts like an oversized motor-peg bearing. The holes for the peg are slightly oversized. The left side of the peg is retained with a short length of the next-larger-size aluminum tube, glued to the motor peg. The right side is retained by a small piece of surgical tubing, which can be removed for motor changes.

New Millennium Sleek-Streek — Karl Gies

Karl Gies has continued his interest in rise-off-ground models by building a New Millennium Sleek-Streek, designed by Clint Brooks. As a kid, Karl had his first successes with AJ Hornets and North Pacific Sleek-Streeks, and he went through many of them. Along the way, Karl and his friends learned about winders, stretch winding, and good rubber. They customized Sleek-Streeks with longer fuselages, different wings, etc., and enjoyed some terrific flights (losing many models to roofs, trees, dogs, and thermals).

Clint has designed what Karl believes is the ultimate Sleek-Streek. The model weighs 29.9 grams (without rubber). Plans are available from the Small Flying Arts website.

Tip stall and washout

Tip stall is a typical characteristic in models with highly tapered wings. When a wingtip stalls, it drops and the airplane can enter a spin. The cure is to wash out the wingtips—raise the wingtips' trailing edge relative to the leading edge. That reduces the angle of attack at the tip, so the tips stall after the center section, resulting in a more straightforward and safer stall.

Walt Mooney discussed tip-stall issues in his Val Peanut Scale construction article in the June 1981 Model Builder magazine. Spitfires exhibit the same tendency. Walt described how he solved the problem with wing washout. Many WWII Russian fighters had extremely tapered wings, including the Yak-3. I built a Yak-3 from Don DeLoach's plans and used slight washout in both wingtips; it is stable and flies great. Don's Yak-3 design was published in the June 2009 Flying Models magazine. He has a few laser-cut short kits remaining for $20 postpaid and the plans (CD0371) for $7 from Flying Models.

Jets, props, and FAC events

Some aeromodellers don't like the look of a propeller on the front of a model jet, but it doesn't bother me. Once the aircraft is airborne, the propeller tends to disappear, especially if painted black.

The FAC now has two events in which models of jets can be flown: Modern Military (open to post‑WWII propeller- or jet-driven aircraft) and the new Rubber Jet Scale (for models of jets).

P‑80 Shooting Star — Dave Mitchell

With the Rubber Jet Scale event in mind, Dave Mitchell modeled the P‑80 Shooting Star, finished in the colors of the post‑WWII U.S. Air Force Acrojets demonstration team. Dave chose that scheme because it looked sharp and because he wanted to model a P‑80 without wingtip tanks—there are many photos of the Acrojet P‑80s flying without tanks.

He built the model for the FAC Rubber Jet Scale class, thinking it could also fly in Modern Military. To his chagrin, Dave learned the P‑80 qualifies as a WWII design because production began before the end of the war. Finished in postwar colors, the Shooting Star cannot compete in a WWII mass‑launch event.

Construction and finish details:

Finish: silver acrylic airbrushed over black tissue.
Lettering and trim: mostly tissue; some computer-generated small lettering.
Insignia: computer-generated, printed on tissue, applied with Elmer's spray adhesive.
Panel lines: applied with a Sharpie marker.
Intake and wing fillets: molded and sanded watercolor paper (very effective).
Wings: friction-fit, pop-off style.

Weights and performance:

Empty weight (with ballast): 45.6 grams.
Test motor: four loops of 3/16‑inch rubber weighing 19 grams.
Wing area: 98.5 square inches.
Wing loading: 0.67 gram/square inch.

Frank Rowsome collaborated with Dave on test flights. As power increased, the P‑80 didn't want to climb until the initial torque burst wore off. Reducing downthrust improved climb. About 0.5 gram of weight was added to the tail to improve the glide; the model then flew an open right-hand pattern with an easy transition into the glide.

The P‑80's first contest was in Raeford, North Carolina, in the fall. The wind dropped at the end of the day and Dave got three or four flights; the final one was at 80% max winds in damp air. Despite the conditions, the jet notched a 90‑second flight to win the FAC Scale event. That flight was impressive enough that Dave has considered retrofitting a DT.

Dave wrote an article about using watercolor paper for fillets, published in the September 2009 Thermalier (the newsletter of the Pensacola Free Flight Team).

To subscribe to Thermalier, send $15 to: George White

Albatros D.V — Doug Beardsworth

Doug Beardsworth used a Golden Age Reproductions kit to build an Albatros D.V, finished in the colors of 36‑victory ace Max Müller's aircraft. The finish is Doug's tried-and-true thinned Floquil‑tinted nitrate dope with plasticizer added, airbrushed over white Esaki.

Doug likes that finish because once the dope sets for a few days it tends to be "cured," becoming stable and warp-resistant. Doug sprays the surfaces, blocks them down flat, and lets them set for a week or so.

The Albatros has proven to be a nice, stable performer. Early flights were pushing close to a minute, so Doug was thrilled.

Specifications:

Empty weight: 49 grams.
Wing area: 99 square inches.
Motor: four strands of 1/8‑inch Supersport rubber (~9 grams).
Propeller: 8-inch Peck-Polymers.
Finish details: quick spritz of tan paint, then brown tissue strips glued on to simulate laminations.

The Albatros incorporates many of Doug's power tricks: an adjustable thrust button, a figure‑8 propeller hook, a forward "Gamble peg," and a rear spool. These allow him to pack in the turns despite the relatively short hook-to-peg length.

US Indoor Championships dates

Dates for the 2010 US Indoor Championships have been set:

Setup day: Tuesday, June 1 (traditionally no flying, but East Tennessee State University in Johnson City said limited practice flying on Tuesday is acceptable).
Competition: Wednesday, June 2 to Sunday, June 6.

Dime Scale and Max‑Fax — Stew Meyers

Stew Meyers is a big fan of Dime Scale models and has been featuring several plans in the Max‑Fax newsletter of the D.C. Maxecuters over the past year. He built all the models shown in the accompanying photo. These 75‑year‑old designs fly amazingly well.

To subscribe to Max‑Fax, send $20 to Stew Meyers.