The tail of the MD-600 uses a NOTAR (No-TAil-Rotor) system, which eliminates the traditional tail rotor by using a variable-pitch fan in the tail boom to create anti-torque. This fan pumps high-volume, low-pressure air out of slots along the tail boom, using the Coandă effect to create a boundary layer that counteracts the main rotor's torque. Yaw control is provided by a rotating direct-jet thruster at the tail boom's end, which varies its thrust in response to pilot pedal inputs, and by the vertical stabilizers at higher speeds. but this was at first hard to figure out how to do this using a jet instead of a tail rotor. but eventually I figured it out and moved onto the other things. overall this build was fun because it was different from the others I have built and this was my first helicopter build. BTW group 3 can help its a gyroscope if you are struggling. Thanks