![]() ![]() The FAA Twilight Calculator helps us determine when we can start logging night flight time. The FAA’s Sunrise / Sunset / Twilight Calculator So they created a handy little calculator to determine when civil twilight ends and begins. Lucky for us, the FAA decided this would probably be too much work for a sane individual who flies frequently, to know how to log night hours in their logbook. What’s that? You don’t have an Air Almanac? You don’t feel like digging through a 900 page book, calculating the angle of the sun, and determining when it will be 6° below the horizon, and converting that to local time each time you go night flying? What are you, LAZY? Just kidding! So if you want to know how to calculate the angle of the sun on the horizon for any day of the year, simply whip out your 900 page book, find the date and time, determine what angle the sun will be at relative to the horizon at what specific time, then convert it to your local time, and easy peezy, there you have it! Now you know when you can log night flying time □ It is an enormous book of around 900 pages that has nothing but massive amounts of data, in table format, of calculations of where the sun, moon, and various other celestial bodies will be for EVERY DAY OF THE YEAR, in 10 minute intervals. The Air Almanac is a publication put out by the The U.S. According to the definition we should be able to go to the Air Almanac and find out when night time will officially begin. Oh, not quite? Okay, let’s keep asking some questions. Well, there you have it, you have all the info you need right there. What Is “Civil Twilight?”Īccording to the AIM and Pilot/Controller Glossary, “civil twilight” is defined as follows: “Civil twilight ends in the evening when the center of the sun’s disk is 6 degrees below the horizon and begins in the morning when the center of the sun’s disk is 6 degrees below the horizon.” ![]() Peace of the scene that came to me with the greatest power the many tokens of home-above all, the thought "I am in England.The FAA’s definition, according to the Aeronautical Information Manual (AIM), and the Pilot/Controller glossary goes as follows: “The time between the end of evening civil twilight and the beginning of morning civil twilight, as published in the Air Almanac, converted to local time.”Ĭlear as day, right? Ha! Sure! Let’s take a look at what we’re dealing with a little closer here. Each little town we passed cast from its windows bright rays upon the tremulous twilight a great bar of fiery redness cut the lower black of the coming night, showing me in shadow the rising of land towards Chatham and towards London. There was odour of the harvest yet in the air and the distant chiming of bells from the Gothic tower which rose above the hamlet and the knoll of green. The hedges were bedecked with their late autumn flowers the teams and smock-frocked men were going home to the gabled houses, and the warm-lit cottages. Before me were the downs of Kent, the open face of an English landscape, the orchard-bound homesteads, the verdurous pasture-land. Fearless in this new thought, I sat in the corner of the first-class carriage reserved for us in such a state of exultation and of hope as few men can have known. So great was my amazement at it all that I went some time without collecting myself to see that the invisible hand of God, which had led me all through, was leading me again-even, as I I will not pause to tell you my own thoughts when I set foot on shore again.
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