I haven't read all the posts on this thread as yet but, I have seen a point expressed here as fact that I feel compelled to debunk as finitely as I can. It has been said tandem rotor helicopters will not enter settling with power as a vortex ring state. With eighteen years in tandem rotor helicopters and nine of those based at 6000'msl and flying to just under 15000'msl, I want you to understand that the tandem rotor helicopter will very certainly suffer this condition if there is only the necessary lack of diligence to allow it to happen. I was twice responsible for not being smart enough for both of us and earned the necessity of recovering the aircraft as my penance. Another rodeo trick you can expect to hear about in the future of tilt rotor aircaft is the prop rotor on the outside of the turn going through ETL when a too fast pedal turn into the wind is made around the opposite prop rotor.