Cessna's and Piper's have dihedral also, and they will still work themselves into a steepening spiral without any help.
I have never noticed such tendency. In steep turns 45-55 degrees most Piper's and Cessna's are very much stable and require only little correction to keep level altitude. I would argue that much bigger and heavier airplanes indeed would go to spiral and usually restricted by 30-35 degrees of bank
Well, you might not have noticed it, but if you look for it you will see that it's there. Personally I think it should be obvious (including in your example of a Cessna or Piper) well before you reach 45 degrees of bank. . .but next tiem you are flying roll into that 45 degree banked turn, and once established just look at your hands or get video of the stick/yoke during the turn and you will certainly observe that you are holding constant aileron pressure opposite the direction of the turn. . .if you were not, you'd be inverted long before you've completed that turn thanks to spiral instability
that is a characteristic of every conventional design.In fact you should be able to observe it in cruise flight even in a Cessna. Go out ona clam day, ttim for cruise as best as you can, make no paower changes after that, if you've got rudder trim, go ahead and center the ball and then put your hands in your lap and your feet on the floor (obviously using no autopilot). It will not take long before you absolutely WILL observe spiral instability even from this best case scenario.
It is definitely there even on modern planes. My Cessna 150 will always work itself into a steepening right spiral if there is no correction from level cruise flight.
It doesn't take much correction to prevent it, but you are fighting it whether you know it or not.
I've noticed in ROF that sometimes my pilot is killed and the plane (usually n28) will continue flying for a long time. Usually in some sort of turn, but it doesn't get steeper. It will just make a lazy spiral down and eventually find the ground.
Also, have noticed that when the pilot dies the controls stay where they were last at. I think they should atleast center, even though that's not totally realistic.
