How many moveable control fins does the typical JDAM tail assembly include?

• A. Two
• B. Three
• C. Four
• D. One

Answer: (B)

Steering a JDAM in flight is done by deflecting fins on its tail to create corrective lift. The typical tail kit uses three moveable fins arranged evenly around the tail. This three-fin setup provides enough control authority to guide the bomb in the needed directions and to achieve stable, responsive maneuvering while keeping the mechanism compact and lightweight. A two-fin arrangement wouldn’t offer enough steering authority, while four fins would add weight and complexity without a proportional gain in control. One movable fin wouldn’t provide meaningful guidance at all. Therefore, three moveable fins is the standard configuration.