What is the optimal speed for achieving the best angle of climb (Vx)?

The best angle of climb speed, known as Vx, is the speed that allows an aircraft to achieve the greatest altitude gain over the least horizontal distance. This is particularly important during takeoff and initial climb phases, especially when there are obstacles near the departure path.

In the context of this question, if the optimal speed for achieving the best angle of climb is identified as 120 knots, this indicates that at this speed, the aircraft can clear obstacles efficiently while maximizing the altitude gain. This speed is typically determined through the aircraft's performance data, which is based on factors including weight, temperature, and altitude.

The other speeds provided are likely higher than what is required for optimal angle of climb, which could lead to increased horizontal distance while climbing, thereby reducing the aircraft's ability to clear obstacles quickly. Knowing the correct Vx is essential for safe operational procedures, especially in Part 135 operations where safety and adherence to regulations are critical.