According to the ROD rule of thumb, how is the rate of descent calculated?

The rate of descent, according to the ROD rule of thumb, is commonly calculated using the ground speed (GS) multiplied by a factor that correlates with a reasonable descent profile in aviation.

In this context, the selection of GS multiplied by 5 is based on the general guideline that for a descent rate in a standard approach situation, multiplying the ground speed by 5 provides a decent approximation for achieving a safe and manageable descent. This means that if an aircraft is flying at a ground speed of, for example, 150 knots, the appropriate descent rate to maintain a smooth glide toward the runway would be approximately 750 feet per minute (150 x 5).

This calculation allows pilots to ensure that they set appropriate vertical speeds during descent for safe landing approaches, promoting efficiency and adhering to standard operating procedures in aviation. The other factors—3, 7, and 10—do not align with the typical descent rates recommended for standard approaches, making them less applicable in this scenario.