Flying Wing Stability Guide
A flying wing has no separate horizontal tail. The wing must carry lift and provide pitch control. This makes center of gravity placement very important. A small aft change can reduce stability. A large forward change can demand more elevon trim.
Why Static Margin Matters
Static margin compares the neutral point with the center of gravity. Positive margin means the neutral point is behind the center of gravity. That usually gives restoring pitch behavior. Many small flying wings begin near three to ten percent margin. Final limits need flight testing and careful simulation.
Geometry Effects
Sweep, taper, chord, and span change the mean aerodynamic chord. They also move the aerodynamic center. More sweep can move the effective chord station rearward. Taper changes area distribution. A light model may still feel unstable if the center of gravity sits too far aft.
Trim and Control
Elevons balance pitching moment. A reflexed airfoil often helps. Negative airfoil moment needs upward elevon trim. Too much trim adds drag and reduces available control. The calculator estimates the required trim from moment coefficient and elevon effectiveness. Treat it as an early design value.
Speed and Loading
Wing loading affects required lift coefficient. Higher mass or smaller area raises the required coefficient. Low speed also raises it. When required lift approaches maximum lift, stall margin becomes poor. A flying wing should be checked at launch, cruise, and landing speeds.
How to Use Results
Use the output to compare design cases. Move the center of gravity and watch static margin. Adjust sweep or chord and review neutral point movement. Check trim angle. If trim is high, revise airfoil, reflex, or center position. Build with a safe forward starting point. Test gradually. Record every change.
Model Limits
This tool uses simplified lifting line ideas. It does not replace wind tunnel data, computational analysis, or safe field testing. Control hinge gaps, twist, washout, and flexible structure can change real behavior. Use conservative margins for first flights. Then refine values with measured glide response and trim logs.
Design Workflow
Start with known dimensions. Enter the expected flying mass. Use cruise speed first. Repeat the calculation for launch speed. Keep clear notes. Compare each setup before cutting parts.