Retreating blade stall is influenced by blade loading, specifically the high blade loading (G loading) factor.

• A. Low blade loading
• B. High blade loading (G loading)
• C. No blade loading
• D. Moderate blade loading

Answer: (B)

The key idea is how much lift the rotor blades have to produce. In forward flight, the blade on the retreating side must operate with lower effective airspeed while the blade on the advancing side sees higher airspeed. For a given blade pitch, this means the retreating blade runs closer to its critical angle of attack as the flight speed increases.

When blade loading is high—meaning the rotor must generate a lot of lift to support weight or maneuvering load—the retreating blade has to work even harder to meet that lift demand. That pushes its angle of attack toward the stall limit, especially because its relative wind is already weaker. So high blade loading reduces the margin to stall on the retreating blade, making retreating blade stall more likely.

Low or no blade loading would decrease the lift demand and widen the stall margin, and moderate loading sits between these extremes, but it is the high loading scenario that most strongly influences the onset of retreating blade stall.