Section 4: Loading & Performance (7–11%)

Weight and balance directly affect the flight characteristics and stability of an sUAS.

Center of Gravity (CG) and Stability

• CG Definition: The theoretical point where the entire weight of the aircraft is concentrated.
• Forward CG: Higher stability, but requires more lift (increasing drag) and leads to slower cruise speeds and higher stall speeds.
• Aft (Rear) CG: Decreases stability; the aircraft may become uncontrollable or unable to recover from a stall.

Load Factor and Turns

In a constant-altitude turn, the "effective weight" of the aircraft increases. This is the load factor, measured in Gs.

• 30° Bank: 1.154 Gs.
• 45° Bank: 1.414 Gs.
• 60° Bank: 2.0 Gs (effective weight doubles).

Impact on Stall Speed

Stall SpeedTurn = Stall SpeedLevel × √(Load Factor)

• Example: At 2 Gs (60° bank), the stall speed is 1.41 times faster than in level flight (a 41% increase).

Angle of Attack (AOA): A stall occurs only when the wing exceeds its Critical AOA, regardless of airspeed.