F5F
F5F is a model airplane - competitive class in the international air sports . The regulations for these competitions are determined by the Fédération Aéronautique Internationale in accordance with the national associations, in Germany the DAeC . The individual characters mean: F = Model flying division, 5 = Electric model flying, F = Electric gliding "entry-level". The corresponding " top class " F5B only differs in terms of the regulations in terms of some performance data .
According to the current regulations (as of 2017), a total amount of energy of 1300 watt-minutes is available to drive the model airplane. The electric motors are driven by a maximum of 6 series-connected cells of a lithium polymer accumulator , the minimum weight of which is 300 grams. 3 different flight tasks have to be completed in one go with the same model weighing at least 1500 grams and having a minimum wing area of 36 dm². This makes a compromise in the coordination of the models indispensable.
Cross-country flight
After the start from the hand of an assistant, there is first a motorized climb. When leaving the throwing hand the timing begins. A 150 m distance must be flown as often as possible in a glider within 200 seconds. Motorized climbing is allowed up to 10 times, but only on one side next to the route.
Gliding
Immediately after the cross-country flight, 10 minutes should be completed without using the engine if possible. Thermal at the airfield is helpful for this. Every second of the engine running time, which is electronically monitored, leads to a point deduction. If there is no longer any part of the amount of energy limited by the regulations available, this will lead to premature landing if the thermal conditions are insufficient .
Target landing
After exactly 10 minutes, the tip of the flight model should come to a standstill within a 10-meter circle. Landings in a 20 or 30 meter circle result in fewer landing points. Outside the largest of the concentrically arranged target circles and generally after more than 630 seconds of sailing time, no more landing points are awarded.