For maximum altitude gain with one engine inoperative, when should the blue radial line be used?

For maximum altitude gain with one engine inoperative, when should the blue radial line be used?

• A. During takeoff
• B. During cruise
• C. During climb and final approach
• D. During descent

Answer: (C)

Using the blue radial line is fundamentally linked to optimizing performance in a multi-engine aircraft when one engine has failed. Specifically for maximum altitude gain, the blue radial line represents the best rate of climb for a given weight and configuration of the aircraft, after accounting for the asymmetric thrust condition created by an inoperative engine.

In the context of the choices provided, during climb and final approach, the use of the blue radial line is particularly relevant. During climb, this line indicates the optimal trajectory that maximizes altitude gain per unit of time and ensures that the aircraft maintains flying speed while effectively managing the performance loss from the inoperative engine.

During final approach, this becomes critical as the altitude needs to be managed carefully while preparing for landing, especially under single-engine conditions which can influence control and performance. Utilizing the blue radial line in these phases helps in maintaining safety and performance standards, allowing for a better assessment of climb capability and ensuring that the aircraft operates within safe parameters despite the loss of one engine.

In contrast, options like takeoff, cruise, and descent do not effectively utilize the blue radial line in the same context. Takeoff primarily focuses on gaining airspeed and transitioning to a climb, while cruise involves maintaining level flight. Descent entails lowering altitude rather