Chapter 10 Night Operations  Introduction The mechanical operation of an airplane at night is no  different than operating the same airplane during the day. The  airplane does not know if it is being operated in the dark or  bright sunlight. It performs and responds to control inputs by  the pilot. The pilot, however, is affected by various aspects  of night operations and must take them into consideration  during night flight operations. Some are actual physical  limitations affecting all pilots while others, such as equipment  requirements, procedures, and emergency situations, must  also be considered.  According to Title 14 of the Code of Federal Regulations  (14 CFR) part 1, Definitions and Abbreviations, night is  defined as the time between the end of evening civil twilight  and the beginning of morning civil twilight. To explain  further, morning civil twilight begins when the geometric  center of the sun is 6° below the horizon and ends at sunrise.  Evening civil twilight begins at sunset and ends when the  geometric center of the sun reaches 6° below the horizon. 