Post on 29-Jan-2016
What Makes a Good Glider
Louie Turekaerospace_pilot@yahoo.com
Fundamentals
• Wing Shape
• The Importance of a Tail
• Balance!
Wing Shape
Leading edge
Trailing edge
Chord
Long, thin wings- Good for gliders
Smooth airfoil shape is essential for good gliding performance
Wings must be strong enough
Wing Structure
Foam wing
Skeleton with covering
Wing Structure
Folded material with spar inside
Wing sweep- Bad idea for gliders
Dihedral- Helps with Stability
The Tail is VERY Important!
No Tail Means No Stability
Proper Sizing and Balance-The rule of fingers
Horizontal tail- 5X smaller than wing area
Vertical tail- 10X smaller than wing area
Canards, efficient but possibly unstable
Flying wing, more efficient but almost guaranteed unstable
Forces on a Glider
Weight
Thrust??????
Drag
Lift
Gravity is source of thrust
Balance – Center of Gravity
Short
Long
Balance Point-Center of Gravity
Wing ~ ¼ back along body
Body length ~ same as wingspan
Wrap Up• Wing Shape- smooth and broad,
but strong enough
• Tail surfaces- Far back and rule of fingers, lightweight tail
• Balance!
Wrap Up• Check that glider balances
• Use ballast to correct flight path
• Practice throwing technique
Rules Review• Minimum 24 inch wingspan, maximum 4”x4” body
• No wheels allowed, no kit materials of any kind allowed, no paper airplanes
• Must carry 16 marbles, sealed in place in sandwich bag
• Weight between 6 and 10 ounces (including 2.1 ounces of marbles)
• Total of 4 flights, score is total distance glided
• If the glider breaks apart, score reduced 25%
Suggestions/Things to Think About• Hobby/craft stores for balsa wood
• Hobby stores have lead edge surface balsa
• Marbles available at craft stores as well
• Small balsa gliders for practice
• Don’t waste material on unneeded things
• Don’t bother with slot construction
Good luck!
Louie Turekaerospace_pilot@yahoo.com