In the United States, for example, landing lights are not required or used for many types of aircraft, but their use is strongly encouraged, both for take-off and landing and during any operations below 10,000 feet (3,000 m) or within ten nautical miles (19 km) of an airport (FAA AIM 4-3-23). According to CFR 14 and FAR Part 91.205, a landing light is required for all aircraft used in commercial operations at night.