Agusta 109 yaw porpoising on A/P flight

[Kyprianos Biris]

I installed the A/P on the A109 that I fly with FS2004 (easy_hap.zip)I have observer that in straight & level flight if you exceed ~100Kts at ~75% Torque the aircraft starts porpoising in the yaw axis (left & right).As soon as I reduce torque to ~60% and it drops below ~90 Kts it stops the effect.Any suggestions ?Does it happen to you ?I suspect it comes from the increased rudder the helicopter needs to stay straight which is something you don't step on when on A/P flight.Kyprianos Biris :-cool[link:avsim.com/greece/hvacc]Hellenic vACChttp://vateud.org/images/vatsim-eurs.gifhttp://vatsim.pilotmedia.fi/statusindicato...tor=OD1&a=a.jpg

[Guest gizmocat]

I've noticed this as well. It happened in the Dauphin at about 90% torque, and it happens in a lot (not all) of other helis at diferent torque/speeds. I take it thet you are refering to the slight osscilating l/r yaw and not something dramatic ?BestsMartin

[Kyprianos Biris]

>helis at diferent torque/speeds. I take it thet you are>refering to the slight osscilating l/r yaw and not something>dramatic ?Yes, that's the one I'm refering to.Kyprianos Biris :-cool[link:avsim.com/greece/hvacc]Hellenic vACChttp://vateud.org/images/vatsim-eurs.gifhttp://vatsim.pilotmedia.fi/statusindicato...tor=OD1&a=a.jpg

[Guest DanielBu]

Hmm - I suspect it has to do with the maximum speed in the flight dynamics file. Like fixed wing aircraft, which start vibrating when exceeding max. speed. I've seen a real heli oscillating a little from left to right - but I don't think it occurs naturally at speed...-Daniel

[Kyprianos Biris]

Daniel I think its created from the yaw counteract that you normally do manually which obviously the autopilot cannot handle properly (no yaw damping)Kyprianos Biris :-cool[link:avsim.com/greece/hvacc]Hellenic vACChttp://vateud.org/images/vatsim-eurs.gifhttp://vatsim.pilotmedia.fi/statusindicato...tor=OD1&a=a.jpg