It can vary, If you have the kind of flu that is a day long then it only lasts a day. But usually it takes about two weeks! ChaCa!
A flu-flu arrow is a type of arrow specifically designed to travel a short distance. Such arrows are particularly useful when shooting at aerial targets or for certain types of recreational archery where the arrow must not travel too far. One of the main uses of these arrows is that they do not get lost as easily if they miss the target.
A flu-flu is a design of fletching, normally made by using long sections of feathers, in most cases six or more sections are used, rather than the traditional three. Alternatively, two long feathers can be spiraled around the end of the arrow shaft. In either case, the excessive fletching serves to generate more drag and slow the arrow down rapidly after a short distance (about 30m). Recreational flu-flus usually have rubber points to add weight and keep the flight slower.