When should a pilot begin to slow down for an assigned holding fix?

A pilot should begin to slow down for an assigned holding fix approximately 3 minutes before reaching it. This timing is important as it allows for a smooth transition to the necessary approach speed and configuration for entering the holding pattern.

The 3-minute guideline helps to ensure that the aircraft can comfortably decelerate and set up for the proper entry into the holding pattern. This standardization provides pilots with enough time to manage the aircraft's speed and configuration without rushing, which is especially crucial in busy airspace or complex situations.

Pilots use this time to prepare for the maneuvers involved in holding, including adjusting speeds and configurations, ensuring they can enter the hold safely and in compliance with air traffic instructions. This approach not only supports safety but also enhances overall operational efficiency.