What is the HOBBS meter used in aviation?

The Hobbs meter is an instrument used to measure the total engine running time of an aircraft. It is typically installed on the instrument panel and is used by pilots to track the aircraft's maintenance requirements and to calculate fuel consumption. The Hobbs meter is a mechanical device that consists of a clock and a counting mechanism. The clock is powered by the aircraft's electrical system and the counting mechanism is driven by a cable that is connected to the engine. As the engine runs, the cable turns the counting mechanism, which records the total engine running time.

The Hobbs meter is a valuable tool for pilots and maintenance personnel. It allows them to track the aircraft's maintenance requirements and to ensure that the aircraft is properly maintained. The Hobbs meter can also be used to calculate fuel consumption. By dividing the total fuel consumed by the total engine running time, pilots can calculate the aircraft's average fuel consumption.