Originally Posted by
Autonomous Collectiv
I've flown 120,130 and 135 fenestron. The 135 is hugely different in it's handling and feel to the other two, a lot of this is probably due to the 135 being built around an autopilot. The 135 is wiggle the toes as compared to muscle up that leg with the 130 and less so 120. The 135 I have also found to be linear whereas the other two very non linear in the thrust available. All of them use a lot of torque though, especially near the limits.
The EC130 fenestron is derived from the EC135 one by symmetry. Aerodynamically it should behave similarly...
If you are interested in the unanticipated yaw topic and if you have time to spend the attached paper was presented last year in Warsaw and might explain the Polish event.