Help analyzing pitch instability of new Crosswind FPV aircraft

@tridge There is a new twin-motor ~2m long-range FPV foamie out known as the Crosswind, by the original designer of the MyTwinDream. Very similar aircraft in many ways, positioned as the refined successor to the MTD. Several of the “alpha test pilots” are experiencing significant instability in pitch. A variety of autopilots are in use, from MFD to ArduPlane to Vector and Pitlab. There is a brief video clip up this morning on RCG of a “tail cam” of an ArduPlane-based Crosswind, showing some of the aircraft’s apparent bad habits. I’ve asked that pilot if he would provide a DF log along with the flight video so we can help diagnose what’s going on. If you can take a look a the clip, I would be curious as to how a well-tuned ArduPlane-based-FC would manage a possibly-flawed-design aircraft. One working theory among the Crosswind group is bad decalage in the design. Another is flex at speed of flight control surfaces. Your insight would be invaluable.

@tridge – DF logs available from the test pilot in his recent post on RCG.


I think you can see what a well tuned AP can do, in Arxangels review.