But officials said he was under visual flight rules, not instrument flight rules. The pilot, Ara Zobayan, was personally certified to fly in bad weather using only his instruments. Visual flight rules are based on the principle of see and avoid. When operation of an aircraft under visual flight rules isn’t safe, often because of inclement weather, a pilot can opt to fly under instrument flight rules. During this type of flight, the pilot navigates only by reference to the instruments in the aircraft cockpit, also known as instrument flight rules, or IFR.

Source: Los Angeles Times January 31, 2020 22:21 UTC