SASS Updraft
The Newsletter of The Seattle Area Soaring Society
Vol. 10, No. 1, January - February, 1998

Upcoming Meetings
Monday, February 9^th, 7 PM; Monday, March 9^th, 7 PM
µ Lake Washington School District Board Room, Redmond µ

Upcoming Events
Ebey's Landing Slope Fun Flies: February 21^st, March 14^th

High Start
by Waid Reynolds (waid@aa.net)

J Calendar Clues. The SASS calendar of soaring events for the year is published at the end of this issue. Be sure to hang onto it. It will not be a regular feature of the newsletter, although specific upcoming events will be called to your attention in each issue. Notice that the calendar includes Northwest Soaring Society contests, and non-soaring events at 60 Acres that we need to be aware of.

J Newsletter Changes. Going into my ninth full year of producing the SASS newsletter I find myself unable to dedicate as much time and energy to it as I have in the past. It is my hope that one or more of our many enthusiastic members will step forward to take over this rewarding task in the near future. Until that happens I want to continue to produce a high quality newsletter. However, this is going to require more help from you, the SASS membership. I no longer have the time to write, collect and transcribe material for the Updraft. Henceforth, the content will be limited to articles and information submitted by you. In other words, the newsletter is going to become a lot shorter unless more of you get involved. My sincere thanks go to Pete Hinze, John Fuller and Charlie Baumgartner, who have already stepped in and made my life a lot easier by taking over the copying, assembly and distribution chores. If there is an enterprising member out there who would like to try their hand at this job, I would be happy to help you get started.

J Equipment Storage. The board of directors is moving ahead to acquire an ocean shipping container for on-site storage of club equipment. Soon, we will have winches and retrievers stored right at the flying field, available for use whenever needed for fun flying, training, and contests.

J Scale Fun Fly. Get to work on those scale sailplanes! There are only 6 months left until Charlie Harris' planned scale fun fly on August 15-16. My 1:4.5 scale Ventus C is progressing. The retractable landing gear is installed, and I'm about ready to start fitting the radio gear. I plan to have the big floater ready for its first flights in early Spring.

J 1998 Tri Cities Slope Fun Fly Date Change. Wil Byers (wilbyers@aol.com) originally scheduled the weekend of April 25-26, 1998 for the annual Slope Fun Fly at Eagle Butte near Richland. Due to a scheduling conflict this date has now been changed to the weekend of April 18-19.

J Model Show Nears. The annual Everett Mall Model Show sponsored by a number of local model clubs is scheduled for February 20 through 21. They are hoping to attract some gliders this year. If you want to display one or more of your sleek slope or thermal beauties, contact Keith Dubendorf, 425-743-6827. There will be prizes awarded for best of show in various categories of which I believe glider is one.

J Gliders Across The Sea(s). Our international friends and members continue to stay in touch. Toshiro Saruwatari wrote and enclosed a copy of his latest stories published in the Japanese Radio Control Technique magazine. It looks like he's making quite a name for himself in Japanese RC soaring circles. Pete Hinze received a letter from Glen Aslin. Glen is doing well in England. He hopes to return to the U.S. next year. Akabee drops an email message this way on occasion. Besides flying RC gliders, he is busy at work designing an unmanned helicopter.

J Coroplast Source. Pete Hinze provided the following information: Coroplast is available from Laird Plastics at 650 South Industrial Way (a bit south of Spokane St. between 6th and Airport way), Phone 206-623-4900. They have it under another of its elevendy-leven different names that I didn't catch but they will know what you mean. It comes in various colors but white is cheapest, to wit:

4' x 8' sheets: 4mm (.158"), $8; 5mm (.197"), $12; 8mm (.315"), $29; 10mm(.394"), $34.

J NW R/C Model Expo. Pete Hinze did his usual excellent work in organizing the SASS booth at the Puyallup show. The club was well represented. The SASS booth, and Wil Byers' Sailplane & Electric Modeler Magazine booth were just about the only evidence of RC gliders at the Expo. Although, in the Bob Holman Plans booth I did notice a fat glass fuse for the WWII German Komet ME-163 (the "football" per Jeff Kasner). It turns out that Holman sells (for $159) a semi kit -- fuse, foam wing cores and plans -- for the 61 inch span Komet. One other glider related booth was selling inexpensive kits for pink foam and tape slope combat gliders.

J PSE. Pete Hinze provided a copy of a recent letter from Puget Sound Energy that confirms the fact that we will not be returning to their facility for club meetings. PSE has converted the auditorium into a 24 hour customer call center. The location will no longer be available to any group for use as a meeting place.

J Passings. It is with sorrow that we report the death in early January of longtime SASS member, Al Blalock. At the request of Al's daughter, the club has made a donation in Al's memory to the Museum of Flight. Q

President's Message
By Bob Brewer, SASS President (airbrew@juno.com)

I decided some time ago that S.A.S.S. had much to offer a person interested in R.C. Soaring. The use of 60 Acres South and sharing flying and building skills with others was the initial attraction, and socializing through club events has been a bonus for both my wife and I. As a recent member (3 years) with more enthusiasm than flying skills, I would like to offer some observations.

• S.A.S.S. serves a widely varied range of interests with participation casual to intense. From staring at the sky for clues to life's mysteries to white knuckle competition. From seeking help to offering help: most members jump at the chance to assist the novice pilot. Meetings, the newsletter and the field itself are the glue that binds all of this together.

• Early members will recall dodging polo ponies and soccer balls with no established priority for use. To form an organized claim to field use, a group of flyers chartered S.A.S.S. in 1989. We all owe a debt of gratitude to those farsighted members as well as to current members who continue to insure the future of our flying site. Today we share 60 Acres S. with other activities (dogs, kites, rockets, mushroom hunters) and are designated by King County as primary volunteer field caretakers. We all contribute to maintaining our good standing with King County. Read S.A.S.S. Field Flying Rules, they are more than suggestions - it doesn't take much imagination to picture a driver on 116th being startled by a wayward glider of any size, resulting in an accident. If you have never had an unplanned landing you have never flown. Launching, particularly with a winch, can be dangerous to children and careless bystanders. 60 Acres S. is not an exclusive soaring field so be patient - I have seen absolute "jerks" intelligently and calmly handled by S.A.S.S. members.
  
• Remember, we have the very inexpensive use of a prime flying site as long as we avoid problems with soccer, motorists and residents on the hill. To this end, none of us should take offense at being reminded of the common sense flying rules.
  
• The Board of Directors, with the blessing of King County, is planning to locate a shipping container on the north edge of the field for equipment storage. This will greatly simplify event planning and take the load off individual members who currently store this stuff at their homes. The county welcomes the high visibility of a storage container as clear notice of the presence of S.A.S.S., and our partnership in caring for the field.
  
• Some of our long range goals, such as improved parking and drainage, have been drawn and submitted to the county at their request. This will take time to realize, so enjoy the mud. With this season's schedule of competition, sport flying, sloping at Whidbey and eastern Washington, Scale and family events and hopefully more trips like Table Mountain we had better get busy at the work bench.

Good Flying
Bob Brewer Q

Sailplane & Electric Modeler Magazine Goes Bimonthly
By Wil Byers (wilbyers@aol.com)

Sailplane & Electric Modeler Magazine (S&EM) is happy to announce the continued growth of our publication. Beginning with Volume 3-3, scheduled for release in March, S&EM will be distributed worldwide. It currently has a U.S. hobby shop distributor (Kalmbach), a U.S. book store / news stand distributor (ADS) and now we have reached an agreement with World Wide distributors to distribute our title world wide. As a result our title will immediately grow by more the 5,000 copies in distribution. This means S&EM has grown to a distribution of nearly 25,000 copies, on a bimonthly basis. In other words, the magazine is spreading the word about the special interest hobby of R/C sailplanes and electric powered airplanes. For further information please contact:

Sailplane & Electric Modeler Magazine, P.O. Box 4267, W. Richland, WA 99353; Phone/FAX: 509-627-0456; email: sailnelec@aol.com; website: www.sailplanemodeler.com Q

International Scale Soaring Association

The ISSA is a new association for scale RC glider flyers. It was chartered by the AMA in 1995. Gary Fogel, ISSA president, recently sent some literature describing the group. As the name would imply, ISSA is dedicated to fostering the growth of RC scale soaring. To that end they are sponsoring and co-sponsoring both slope soaring and thermal soaring events for owners of scale RC gliders. In fact, Gary has been assisting Charlie Harris in developing the format for the SASS scale meet coming up in August.

Gary says that ISSA hopes to become a medium of exchange for information, documentation, activities, etc. to promote the hobby. The group's newsletter, Towline, is published quarterly by editor Randy Warner to help get the word out. To further the flow of information they have established a web site, maintained by Adrian Cuesta of Spain. Membership in the group costs only $15 per year. If you have any interest in scale RC gliders this looks like a worthwhile group to get involved in. A couple of the upcoming events are the Torrey Pines Scale Soaring Classic (slope and thermal) on March 28^th and the ISSA April 18^th Fun Fly, which will include informal cross country soaring for those who are interested. Other events are tentatively planned for September and October. All are in southern California, of course. A monthly postal contest, which is something that you local scale guys could get involved in, is also being sponsored by ISSA. Events are thermal duration and cross country with classes for vintage and modern gliders.

I have handed off the ISSA information, which included club bylaws and a membership application that could be photocopied, to Bob Brewer. You can contact Gary Fogel by phone, email, or snail mail and he will send you an information package:

Gary Fogel, 3615 Watseka Ave. #101, Los Angeles, CA 90034, phone: 310-838-6068, email: gfogel@ucla.edu. The ISSA web site URL is http://www.arrakis.es/^odri/issa/html. Q

Extracts From The Internet

If you are interested in simple, low cost airborne flight computer systems, this is the place to look: Taniwha Flight Computer Home Page -- http://www.taniwha.com/~paul/fc/index.html.

Subject: Weather Station for Discovery Park Winds
From: Russ Young (russ@transtechgroup.com)
Sent: Saturday, January 17, 1998 6:58 AM
Am I the only one to know about the www site that displays the weather conditions at West Point (just down the hill from Discovery Park)?. If I am, I thought others might like to know about the site -- http://www.nws.fsu.edu/B/buoy?station=wpow1. Q

The Design History of The F-21 Predator
By Rick Powers (rpvi@aol.com)

(Rick produces this new all-EPP foam bird)

My first involvement with radio control gliders occurred in 1971. I acquired a Windward (the smaller sibling of the Windfree), equipped with Kraft radio gear. We were amazed at the degree of miniaturization in the Kraft system but compared to today’s equipment it was bulky and heavy. With this system I learned the basics of slope soaring and amazed my father at how quickly I became proficient at slope soaring.

Years later, after college, I got back into R/C soaring. The new generation of R/C gear also made flying and construction easier, thus adding to the fun. I returned to basics, flying a generic 2 meter balsa airplane, just to re-hone my skills. One thing let to another, and soon our group of soaring buddies sought out slopes with more radical winds which required a higher level of skill.

In our particular region, the Santa Cruz mountains above Palo Alto, we can find flying sites with fantastic lift as Pacific winds blow over the San Francisco peninsula mountains on their way inland. We found that the basic 2-meter balsa airplanes were not sufficiently tough to survive the repeated rough landings typical of these rugged flying sites.

I then met a flier who had a "Geek", an innovative slope soarer made by Steve Hinderks' Birdworks in Oregon and now, unfortunately, no longer in production. This had to be the answer! I bought a kit, then built and flew it. The use of plastic composites and durable foam in the Geek was well before its time. This was our first experience with an "indestructible" airplane. The Geek could survive the most violent crashes due to its construction.

We had lots of fun flying in driving rain, darting about with our Geeks, loving every minute of it. We even had some "combat" collisions, and enjoyed the excitement of watching our Geeks tumble out of the sky. But there was a problem. While the Geek was superb in very high winds, it just didn't fly very well in lighter lift. With its small wing span it had a fairly heavy wing loading, and needed lots of lift to fly. We found it flew best in near storm conditions.

We then discovered Dave's Aircraft Works foamie fighters. Dave Sanders is the respected leader in PSS slope gliders, and we built and flew kits of his P-51 Mustang. The foamie fighters are a great series, and they fly well. We learned how to line-up an attack, and how to fly out of a collision (the two basic combat skills), and had tons of fun.

During this time, I had the good fortune to pick up a used SR-7, a great design made by Bob Martin. It has a duralene fuselage and a 1/64" ply-skinned white foam wing. The SR-7 is a screamer on the slopes! With this airplane I was able to do more consecutive rolls and to achieve higher speeds than I had ever before in my life. The SR-7 was a great design, but unfortunately it was heavy and did not survive rough landings or crashes very well.

So you can guess the next step. Why not learn from the advances made in the SR-7, and make them available for the sport flyer in EPP? What we liked about the SR-7 was its highly tapered wing planform, a design that allows the airplane to generate fast roll rates. We knew that the SR-7 was fast, highly maneuverable, but it was heavy and therefore needed strong winds to keep it aloft. Besides, despite the duralene fuselage, it still suffered damage during rough landings or crashes.

We went to the drawing board, and using some of the basic parameters of the SR-7 adapted a somewhat similar planform to an EPP design. One of the technical challenges was how to cut EPP foam with a high degree of taper. If one looks closely at the currently available EPP designs, one will notice that most of the wing planforms are made with minimal taper. This is due to the fact that it is difficult to cut a wing core from EPP with significant taper, more difficult than from blue or white foam. What generally happens is that the cutting wire is too cold at the root and too hot at the tip of the wing core.

We have found a proprietary method for making a highly tapered cut with EPP wing cores. It involves fine tuning the cutting wire in terms of diameter, current, temperature, and cutting speed so that we obtain a good cut all along the wing. This takes a considerable amount of skill, much more so than for the average mildly tapered wing. Our wing cutting expert has mastered this, and is turning out excellent quality wings with a high degree of taper. Measured without the ailerons, our cores have a 12" root chord and 3" tip chord, for a taper ratio of 0.25. Full span ailerons (2" chord) are used, and they give our EPP design its tremendous roll rate (note that the ailerons area full 40% of chord at the tip!) The large (% of chord) ailerons coupled with the highly tapered wind results in high rotational forces (from the ailerons) and a low damping in roll (due to the distribution of the wing area). For a wing spar we have chosen wound-glass-fiber/black epoxy tubes, which are light and strong. This spar combined with EPP cores make for a wing that is quite nearly indestructible. I have yet to see one fail!

We also spoke to our EPP manufacturer, and were able to obtain a higher density EPP for the fuselage of our new design. Most EPP is 1.3 lb/ft³ density, and but decided to use 1.9 lb/ft³ EPP for our fuselage (the wing uses 1.3 lb/ft³ density EPP). This gives us a fuselage that is quite nearly indestructible. It efficiently and safely houses the radio gear. Tail surfaces are Coroplast. We chose the RG-15 airfoil for its proven performance (good lift with good speed penetration). This airplane is able to achieve greater top speeds because of its special low-drag fuselage coupled with the modestly cambered airfoil.

There is a significant reduction in drag with a highly tapered wing. When pulling Gs (i.e., at high lift coefficients) the induced drag of an untapered wing results in a significant increase in total drag. The differences in actual flight are noticeable and are truly amazing!

Put it all together and you have one great looking airplane that has outstanding flight performance. It will soar well in light air; it will do high rate axial rolls; it will fly inverted with ease, and will do inside and outside loops. It will thrill both the pilot as well as onlookers. In a combat zone, it can hover above the pack, then quickly dive and swoop on an opponent. This airplane can score kills like no other. And all this while looking great!

The name of the airplane is the F-21 "Predator". It is available from REV Industries, Palo Alto CA (650) 493-5502 ($59 + shipping). Email to rpvi@aol.com. There is an informative web page at http://members.aol.com/Rpvi/F-21.html. Q

1997 Financial Report
By Charles Baumgartner, Treasurer

Other Numbers of Interest:

Membership: 118
Number of New Members (new names): 25
Number of 1996 Members who did not renew: 27
Number of Members who had paid dues for 2 or more years: 7 Q

Unclassified Ads
(To advertise glider related stuff, contact Waid Reynolds, 206-772-0291, or send email to waid@aa.net)

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