In what scenario is a maximum tailwind of 5 knots acceptable?

The scenario in which a maximum tailwind of 5 knots is acceptable is during steep approaches. This is because steep approaches often occur in environments where overcoming obstacles or terrain is a priority, and the aircraft's approach profile can be managed within those conditions. The King Air 350 is engineered to handle certain environmental parameters, including moderate tailwinds, during these specific situations.

Using a tailwind during steep approaches requires careful management of airspeed and descent rate, which the aircraft's systems can handle effectively, especially given the added control provided by flaps and power management during such an approach. In contrast, other scenarios like standard landing procedures, go-arounds, or takeoff typically require more stringent limitations on tailwinds to ensure stable flight conditions and sufficient performance margins.