Alfa Model EDF 60/25 ducted fan is designed for the Mega 16/7/4(5) motor and for AC motors with similar performance characteristics ( input 200W; the design velocity of flight is 25 m/s. The ducted fan can power models of the 600 grams maximum weight, whose wing area should be 12 to 15 dm2. The weight affects the flight performance of the ducted fan-propelled model much more than it does to a propeller-driven one, therefore it is advisable to save really every gram. The efficiency of the ducted fan is vitally dependent on both the accuracy of the assembly of the device itself, and on its correct installation into the model. Please devote therefore the maximum attention to the following information.