Enhanced 4-axis FD in the 139 has an Autohover function - push the button and it'll sit just where you put it. You move it around the place with the cyclic trim for left/right or forwards/backwards and the collective trim to yaw left/right or go up/down. The book says you must be above 30ft agl but it will descend to 15ft in HOV Mode. I can't remember the figures off the top of my head (I rarely use it) but I think it will function up to 60kts GS. Given that the FD drops out at 60KIAS, you could make a sharpish transition from one to the other by some swift button pushing but there is no formal transition from a coupled approach to a coupled hover. The SAR kit adds more software and a couple extra buttons on the FD panel. What the plans are for the 109, I've no idea but CarryOCopter's remarks about SAS1 and th pedlas are worth noting.