Jim covered the history of the airfoils used in past flying wings, showing the deficiencies in each. The fauvel was one of the more successful but with a 17% height, the airflow separated at low speeds giving a poor performance but at high speeds this was not a problem and it was fairly efficient . For the XM1 flying plank that Jim constructed he reduced this to about 12% and the resulting airfoil was greatly improved. It is only in the last few years that positive pitching airfoils for flying wings have been able to be studied with computer programs. It was interesting to note that with many of Jim's new airfoils he can obtain very high values for the lift co-efficient while maintaining a positive pitching moment along with low drag.

Finally this class made sense to me! We worked through wing spars with wood and carbon. We discussed the proper method of attachment for the carbon rods to the wing fittings. One of the interesting points to ponder is that the carbon rods are so strong and light that while we created a 12 g spar the deflection was over 20 inches per g. This was unacceptible and we had to go for a 20 g spar to get a deflection of only 5 -10 inches per g. While I am not fully fluent in spar design I can now converse with some measure of competence. I immediatly rushed home to look at my Windrose spar, applied the formulas and found that yes indeed the windrose spar would be good for about 9- 10 g's.
SATURDAY NOVEMBER 14, 1998
Theory behind flying wings, an introductory course:
One of the questions that has been lurking the the background of flying wings was Jim's reasoning for not endorsing the swept back wing. The sept back wing has poor spin characteristics, high drag, especially for tip rudders, difficult spar construction and the the necessity for washout only compounds the drag and spin problems. The inefficient airflow over the wing and many other details make the swept back wing unsuitable for an efficient, safe flying wing. And after flying the monarch I believe Jim is absolutely correct! Jim's flying wings all have a stable airfoil,(positive pitdhing moment) and a straight or slightly forwardswept wing.

As the glider approaches a stall the airflow separates over the aft part of the trailing edge and the elevator attached to the aft part of the wing is no longer effective so you cannot stall. Also as the wing speeds up, the tendency for the wing is to pitch up to slow the wing and give strong stick forces.

OPTIONAL COURSES:

Canopy making: Make a canopy : We made a canopy! It was rather disconcerting to see 320 degree heat applied tova canopy and then to watch Jim vacuum it to shape... but it happend right before our eyes!

Introduction to metal parts fabrication.Tim Tangquay gave us a good overview of metal part construction. This renewed a lot of my understanding and cautionary notes when working with metal.

Making a mold from Foam Plug. All of us put on our gloves and pitched in to build some molds for D tube wing ribs. The first blue colored gel coat partially hardened was followed by a similar coating, then the "magic" glass cloth was placed on. The result was very few bubbles and successful molds. We also had the delight in participating in the newly developed D tube skin for the prototype pioneer. Again the result was very satisfying although at first we were rather perplexed at the concave undersurface until we realized that we had neglected to have an airhole between the ribs in the D tube and the trapped cool air had drawn in the underside of the sample D tube! another lesson.

We also had a demonstrattion of the "Raptor" a creation of Mat Kollman's who attended the workshop. I was very imporessed with his workmanship and concept. Being an avid hang gldier pilot this really peaked my interest. Matt has been offered a position with us doing the fuselages and D tubes for the kits.

THURSDAY, november 12, 1998
Airfoils for Flying wings: 9-5

Jim Marske ready for another class!

FRIDAY, NOVEMBER 13, 1998
Stress calculations for spar design:

SATURDAY NOVEMBER 14, 1998

OPTIONAL COURSES:

Yes, Pat thats a real canopy just out of the oven! Curt and Fred look on.

Ok, here are the D tube rib molds being made. Lots of hands and concentration!

Jim Marske ready to insert a rib into a sample D tube Wing skin mold.

A sneak preview: Pioneer 3 fuselage plug. Kits are projected for the fall of 2001.