Which of these is NOT powered by the aircraft's electrical system?

The landing gear system in many aircraft is commonly operated by mechanical or hydraulic systems rather than being solely powered by the electrical system. While some aircraft do have electrically operated landing gear, many utilize a combination of hydraulic systems that rely on engine-driven pumps, which may not be directly connected to the aircraft's electrical system.

In contrast, taxi lights, turn coordinators, and strobe lights all require electrical power to function. Taxi lights illuminate the runway and taxiway during ground operations, the turn coordinator is an instrument that provides information about the aircraft's turn rate, and strobe lights enhance the aircraft's visibility during flight. All of these components are designed to operate using the aircraft's electrical power supply.