For Jet Logs, what type of winds should be used to compute ground speed?

To compute ground speed for Jet Logs, forecast winds should be used. The reason for this is that forecast winds provide the projected atmospheric conditions affecting aircraft movement along a route. Since ground speed is influenced primarily by the wind direction and speed at the altitude of travel, it's crucial to utilize forecasts that accurately represent expected conditions during the flight rather than relying on historical or average winds which may not be reflective of the current flight environment.

Using actual winds could lead to discrepancies as they change dynamically during the flight. Historical winds offer no predictive insight into the current journey, making them less useful for ground speed calculations. Average winds might not account for specific and potentially significant variations that will affect flight performance. Therefore, using forecast winds aligns with the goal of providing the most accurate estimation of ground speed expected on the planned flight path.