Part of reaching the 'at one' state for me is the aeroplane must give the pilot unconscious feedback through the controls. The Chipmunk does this - I swear you can 'feel' through the stick the CP moving forward on the wing after a 'back of the drag curve' hoink into the air off a muddy field while accelerating in ground effect.
The Chippy also demands you use your feet to obviate adverse yaw; those Frise ailerons on Cessnas etc might reduce the need for rudder when rolling the aeroplane into and out of turns but they sure screw up the 'feel' and feedback. And while the Chippy's rudder pedals tell your feet what the air is doing around that control surface, all I feel through a 172's rudder pedals is the springs in the nosewheel steering circuit! All that washout spoils the roll response as well; but the elevator is nice! The co-ordination of ailerons, rudder, and elevator is wrong, though. The compromised feedback in a 172's controls means for me it's unlikely ever to be an 'at one' aeroplane.
If an aeroplane has nice handling, unencumbered friction-free finger-light flying controls, pure and well co-ordinated control response with no bodges like Frise ailerons, it stands a good chance of becoming an 'at one with' machine, given time.
The Yak 52 ticks those boxes as well, and given time, for me, that could qualify too.
Last edited by Shaggy Sheep Driver; 22nd Mar 2015 at 19:52.