Machinbird, All that you probably ever wanted to know about spring failures can be found here:
thanks fore the link ,
if worn is the wrong word, then sorry I meant relaxation.... is it one spring for pitch or one for push and one for pull into the sidestick??? If I remember well gums has shown a diagram of the energy vs move of the sidestick in thread 3(?) with a kink in the line, so mayby there works more than one spring in each direction