Wondering Where to Start?

Science Olympiad 1999/2000 Airplane Specifications

• Mass without motor at least 8 grams.
• Maximum wing span is 50 cm.
• Maximum wing chord is 12 cm.
• Maximum stab span 35 cm.
• Propeller must be commercially molded, plastic, two blades and not to exceed 20 cm.
• Mass of single loop motor (including O-ring) is not to exceed 2 grams.
• Landing gear consists of two 3/4 inch wheels separated by at least 6 cm.

Here are some of Dick Baxter's opinions on "starting point" kits and designs for the Science Olympiad 1999/2000 airplane competitions.

While specifically addressing the constraints of the Science Olympiad rules, these thoughts are also a good start for the Technology Student Association competition.

Some References

S.O. Advisors Volunteer & Help Wanted lists

Cottage Wings materials supplier's list

An Introductory Guideline to Building and Flying Model Aeroplanes
(While aimed more at sport and scale models, it has a lot to offer.)

3 books you might want:

1. Rubber Powered Model Airplanes by Don Ross.
   $14.95 plus $2 s&h? Order from
   Carstens Publications
   Box 700
   Newton, N.J. 07860
   1-800-474-6995

   Or online from Hannan's Runway at www.hrunway.com

2. Indoor Flying Models by Lew Gitlow
   $22 plus $5 s&h. but minimum order is @$25 so you might as well order $3 of something else too. Possibly a Slow Poke kit to get started, see below.
   Indoor Model Supply
   Box 2020
   Florence, Oregon 97439
   541-902-8508

   Also available online from Hannan's Runway

3. Model Aircraft Aerodynamics by Martin Simons
   Published by Argus Books
   1 Golden Square
   London W1R3AB, England
   ISBN 0 85242 9150
   My copy cost $14.25 about 10 years ago. I think you can find this on Amazon.com or Hannans.

   The Simons book is a college level aero engineering text about model airplanes. Simons does not pull punches but the book is readable around the equations if you really like this stuff. Simons isn't about construction but will tell you how things really work.

Some of the model designs or kits that make good starting places for the S.O. competition.

• Midwest Product's Right Flier. Slightly too small and rather too heavy. Includes landing gear. Available as bulk kit for 8 models. Right fliers and variations have won several SO competitions in the past. The Right Flier and some variations are described at http://www.midwestproducts.com/eduhome.htm

• Midwest Product's Sorcerer. Midwest Industries entry in the Science Olympiad kit selection. Designed by Tom Sanders who pretty much invented the SO airplane competition. It looks pretty ease to build and should fly very well.

  Sorcerer, kit # 525, $29.95 plus S&H (two basic models can be built)...
  Features:

  1. Laser Cut 1/16" cambered ribs, spoked wheels (3/4" diam) and gussets.
  2. 4 propellers, 2ea 8" Peck Grays, 2ea 6" Tern Aero Style
  3. Esaki Tissue
  4. Design: High wing, tip dihedral, two pc fuselage, lifting stab. fuselage- motorstick (laminated for torsional strength) and tailboom. Uses "boomlock" to hold tailboom and give trim adjustments.
  5. Easy to read plan with iso views of critial assemblies, extensive "teaching" instructions.
  6. Midwest Microcut balsa wood

  Midwest Products
  400 So. Indiana St.
  Box 564
  Hobart, In 46342
  Phone 1-800-348-3497... ask for Tom Sanders

• Peck Polymer's Skybunny. A little too small and much too heavy. Stretch it and lighten it up.
  Email PPModels@aol.com
  Peck Polymers Web site
  phone 619-448-1818 Ask for Sandy Peck, she may have other useful stuff too.

• Mace p-18. Again a little small. Structure is about right. email Don Mace at macex@ibm.net

• Indoor Model Supply Slo Poke. Also a little small and maybe a little light structure. Lew Gitlow at Indoor Model Supply has already designed a plane to match the SO 2000 specifications.
  I.M.S.
  Box 2020
  Florence, Or. 97439

• Double Whammy plan from the October or November 1999 Model Aviation magazine. A little small, reasonable structure, but needs a cambered wing.

• "Blatter 40" plans for downloading. A little small but about right structure and includes landing gear. There is also a Blatter version aimed at the S.O.

• AeroRacers Science Superlightning AF-17 I haven't seen an actually model, but the spec and picture on the web site look good and match the year 2000 SO rules.

  Aeroracers Inc.
  888-268-2376 - toll free
  310 519 8560 - combined phone and fax number
  www.aeroracers.com
  proprietor is Luc Bausch. He also stocks a variety of odd size prestripped rubber.

• Look for vendor addresses on Cottage Wings.

• Look for Model Aviation on AMA web site

• Possibly the Hangar Rat which is on the web somewhere. (url folks?)

• Surf the web, for free flight, indoor models etc.

Probable mods most kits will need.

Basically, scale (up or down) your kit to 50 cm span, Use a cambered (curved) airfoil. Scrape a 9" Peck Polymers prop down to 2 to 2.5 grams (before trimming) and then trim to allowed size. Do not allow the model to be overweight by more than 1/2 gram. Practice a lot These airplanes will probably want a loop of .075 to .080 wide Tan II rubber to get best duration. 1/16 is too thin and 3/32 is too wide.

You will find that most (maybe all) kits you can find are too big or too small. Bite the bullet and scale the sizes to the max allowed wing span, and maybe wing chord. Rescale the tail as well and make the motor stick as long as the motor that works for you. Use a tail boom if the motor stick is too short. Obviously you need to do some trial and error modifications to get the best airplane.

I tell beginners they need to build at least 3 airplanes. Number 1 is to get errors out of your system and to use for flying practice. Number 2 is a prototype competition airplane you use to get wood sizes and component weights right and correct errors in incidence, tail size, dihedral and so on. If number 2 does not fly to suit you modify it until it does. Don't hesitate to replace parts you think are not right. This is an experiment in performance optimization. Also use number 2 for flying practice. Number 3 is your competition airplane. It should weigh between 8 and 8.5 grams and should not surprise you in flight if you modified number 2 enough before you were done with it. Fly number 3 enough so you can pretty consistently predict what it will do. If you have time and energy, build number 4 as a spare competition airplane. Make parts interchangeable with number 3, but assemble it and fly it until it is reliable.

My guess is that winning times for the 1999/2000 season will be on the high side of 2 1/2 minutes in High School and maybe 3 minutes in Middle school. The middle school students don't have to drag a landing gear around. To be competitive, you should work for at least 2 minutes under a 20+ foot ceiling, even at the local level.

good flying

Dick Baxter