Final answer:
To fix an unstable spiral mode on a glider, you can adjust the wing design and weight distribution, such as the dihedral angle and center of gravity. Proper alignment and balance of wings and control surfaces is also important for stable flight.
Step-by-step explanation:
On a glider, you can modify the wing design and weight distribution to correct an unstable spiral mode. Increasing the wings' dihedral angle—the upward angle of the wings in relation to the horizontal plane—is one way to achieve this. By enabling the glider to return to its starting position when disturbed, this enhances stability.
Changing the glider's center of gravity is an additional choice. The glider gains stability when the center of gravity is moved in closer proximity to the wings. This can be accomplished by shifting the glider's weight or adding ballast to particular sections.
Additionally, ensuring that the wings and control surfaces are properly aligned and balanced is crucial for stable flight. Any imbalances or misalignments can cause the glider to behave erratically. Regular maintenance and inspections can help identify and rectify such issues.