Which flight time may be logged as instrument time when on an instrument flight plan?

When operating under an instrument flight plan, the specific time that may be logged as instrument time is the duration spent controlling the aircraft solely by reference to the flight instruments. This is important because instrument time is defined by the nature of the flying being conducted. The requirement is to have the aircraft controlled under conditions that necessitate reliance on instruments due to limitations in visibility or weather.

The distinction lies in the fact that instrument time is particularly recognized for the purpose of training and meeting FAA qualifications. Thus, while any time logged under IFR conditions might seem applicable, it is only the time when you are actively and solely relying on the instruments for aircraft control that counts as instrument time. This ensures that the logged time reflects your skills and experience required to operate effectively in actual instrument flight conditions.