🔍 Key Concepts

• Controllable-pitch propeller (CPP) vs fixed-pitch propeller (FPP): mechanical complexity and operating flexibility • How propeller pitch affects maneuverability, fuel economy, and handling characteristics • Typical advantages and disadvantages listed for CPPs in standard marine engineering references

💭 Think About

• Think about what a controllable-pitch propeller is specifically designed to improve compared with a fixed-pitch propeller. Which options actually sound like benefits rather than drawbacks? • Consider which choice most likely results from the added mechanical complexity and variable blade angle of a CPP compared to the simplicity of a solid, fixed-pitch propeller. • Ask yourself: which of these problems would you expect more from a simple, non-adjustable system, and which could arise from a more sophisticated, adjustable system?

✅ Before You Answer

• Eliminate any option that clearly describes a typical advantage of CPPs (for example, better control when going astern). • Consider whether fuel consumption is generally improved or worsened when you can match pitch to engine loading and operating conditions. • Focus on any answer that mentions handling characteristics or behavior that might feel different to a watch officer used to a fixed-pitch propeller.