General Layout

The Eagle design concept has been moving ahead on paper, and even a bit in hardware. I got some ideas from studying a few old hang glider designs, especially Bill Wolf's Valkyrie, and Klaus Hill's Fledgling/Voyager. Some sweepback is desirable to get the benefit of some directional stability and yaw/roll control from a winglet & tip rudder arrangement, but keeping the sweep angle to a minimum is important for attaining a lightweight structure. A minimal amount of washout will be used to avoid tip stalls and maintain good lift distribution throughout the speed range, as seen below.



Since washout and sweep will be very modest, the main source of pitch stability must be a positive pitching moment airfoil section. This might be something like the Eppler E 335, or Hepperle MH 78... exact airfoil section(s) to be selected is TBD. I have more-or-less settled these dimensions for the Eagle:


Sweep = 5 degrees (1/4 chord)
Root Chord = 5 feet
Tip Chord = 3 feet
Wing Span = 40 feet (w/o winglets)
Wing Area = 160 sq. ft. (w/o winglets)
Winglet Height = 4 feet
Winglet Cant = 30 degrees
Winglet Tow-in = 1.5 degrees
Dihedral = 2 degrees
Washout = 2.5 degrees



Here is a picture of the planform with MAC and CG location... happy landings, all!!