I am currently designing a tiltwing aircraft. Designed in solidworks and remodeled in X-plane flight simulator for flight tests. During transition flights from hover to forward flights I am experiencing sudden uncontrollable nose-down pitching moments from which the aircraft cannot recover. Upon certain intuitive improvements such as increasing engine power, full transition is now possible, at a very high sink rate, which eventually ends up in a crash. I cannot increase power indefinitely, i also cannot increase wing area indefinitely.
Are there any other parameters which can be adjusted and does the wing tiltrate also affect the transition. My wing tiltrate in 8 degrees per second. I increased it to 14, still the same problem, with an earlier stall.
Dear Devan Rudolph
To my humble knowledge, I guess the main challenge is to keep the aerodynamic regime in the linear mode. Any deviation from the linear aerodynamic regime could drastically lead in instability of the flight motion. The main causes for such a deviation could be: High-rate movement of the tilt-wing. High angle-of-attack movement of the tilt-wing, or rotor blade (rapid change in angle-of-attack). Ground effect when near earth surface. Sudden maneuver of the tilt-wing or the aircraft.
Perhaps one solution might be to tilt the wings stepwise to gain enough speed for aerodynamic lift. It sounds like in the middle angle range the wing stalls and the rotors don't provide enough lift any more.
