Pilots should carry at least two flashlights plus extra batteries when flying at night. Flashlights are critical for reading charts as well as the aircraft instruments in the event of an electrical failure. In the past red lighting was recommended based on the idea that red light did not diminish night vision as much as white light. This idea has now been proven false and modern aircraft cockpits do not incorporate red lighting. However, bright lights definitely affect night vision, so flashlights with a dimmable beam are recommended.