What does a descending rate of climb indicate?

A descending rate of climb indicates that the aircraft is losing altitude. When an aircraft has a descending rate, it means that the vertical speed is negative, which signifies that it is descending through the air rather than ascending. This can occur for various reasons, such as when the pilot intentionally reduces power or alters the aircraft's configuration to descend, or if the aircraft is slowing down after reaching cruise altitude.

In contrast, maintaining altitude would imply that the rate of climb is zero, indicating that the aircraft is neither gaining nor losing height. Gaining altitude means that the aircraft's vertical speed is positive, which is not the case with a descending rate. Performing a controlled descent, while it may seem similar, focuses more on the intention behind the descent rather than simply losing altitude. Hence, a descending rate of climb directly translates to the aircraft actively losing altitude.