What speed is recommended for descent in alternate scenarios?

The recommended speed of 0.77 IMN transitioning to 320 KIAS for descent in alternate scenarios is based on balancing aerodynamic efficiency and operational safety.

A speed of 0.77 IMN provides an optimal airspeed for maintaining controlled descent while maximizing lift-to-drag ratios and improving fuel efficiency. The transition to 320 KIAS ensures that the aircraft operates within the structural limits while descending. This combination allows for a stable descent profile, which is crucial in alternate scenarios where precise control and operational performance become paramount.

Additionally, 320 KIAS is typically within the realm of upper speed limits for jet aircraft during descent, allowing pilots to ensure that they are able to adjust their airspeed adequately for safe handling and timely integration into the approach or landing phase. This kind of speed management is vital in various flight scenarios to prevent adverse situations, such as stalling or exceeding structural limits.

Therefore, this speed recommendation reflects a well-considered approach to achieving safety and efficiency during critical flight phases.