What is the recommended initial action for ideal pitot heat usage?

The recommended initial action for ideal pitot heat usage is to turn it on a few minutes prior to entering instrument meteorological conditions (IMC) when the outside air temperature is below 10 degrees Celsius. This approach is vital because it helps prevent ice from forming on the pitot tube, which can disrupt the airspeed readings that are critical for safe flight operations. Ice formation can occur when moisture-laden air, at or below freezing temperature, comes into contact with the pitot tube. By activating the pitot heat before entering IMC, a pilot ensures that the pitot tube remains clear and functional, effectively maintaining accurate readings during potentially hazardous conditions.

Engaging the pitot heat too late, such as immediately upon entering IMC, may not provide enough time for the heat to effectively melt any ice that has already formed. Turning on the heat after takeoff, regardless of temperature, lacks the proactive nature that is critical for good flying practice, and waiting until after landing disregards the need for reliable airspeed indications while in flight. Hence, activating the pitot heat before entering IMC at lower temperatures is the best practice for ensuring safety and performance.