In how many minutes should a C-130 slow down according to aviation protocols?

The appropriate time for a C-130 to slow down, according to aviation protocols, is generally around 3 minutes prior to reaching the designated drop zone or area where the aircraft needs to prepare for landing or dropping cargo. This duration allows the aircraft to decelerate in a controlled manner, ensuring safety and stability during the approach phase.

Slowing down too quickly can create turbulence or unstable flight conditions, which could compromise the effectiveness of the drop, especially when parachutists are involved. By adhering to the 3-minute protocol, pilots can better manage the aircraft's speed and maintain optimal flight dynamics, allowing for a smooth and safe operation, whether for personnel jumping or equipment being released.

In this scenario, the other options reflect either insufficient or excessive time frames for deceleration, which do not align with established protocols, thereby emphasizing the importance of the correct timing for safety and operational effectiveness.