Where are the high and low pitch stops of a Hamilton Standard constant-speed propeller located?

Where are the high and low pitch stops of a Hamilton Standard constant-speed propeller located?

• A. In the hub
• B. In the governor
• C. In the nacelle
• D. In the counterweight assembly

Answer: (D)

In a Hamilton Standard constant-speed propeller, the limits for blade angle travel—the high and low pitch stops—are built into the counterweight assembly. As the governor commands a change in pitch, hydraulic pressure moves the blades, but the actual extremes of motion are limited by surfaces in the counterweight assembly. This arrangement guarantees safe, well-defined maximum coarse (high pitch) and fine (low pitch) angles and helps ensure reliable feathering and protection against over-travel, even if the hydraulic system or governor behavior changes. The stops aren’t located in the hub or nacelle, and the governor provides the control signal rather than the physical limits.

In a Hamilton Standard constant-speed propeller, the limits for blade angle travel—the high and low pitch stops—are built into the counterweight assembly. As the governor commands a change in pitch, hydraulic pressure moves the blades, but the actual extremes of motion are limited by surfaces in the counterweight assembly. This arrangement guarantees safe, well-defined maximum coarse (high pitch) and fine (low pitch) angles and helps ensure reliable feathering and protection against over-travel, even if the hydraulic system or governor behavior changes. The stops aren’t located in the hub or nacelle, and the governor provides the control signal rather than the physical limits.