Hi Howard,
I am experiencing the same. The default camera view under the S key is Spot, Tower, Flyby and Ground view. With all my addon aircraft the Spot view is a smooth pan. Release the hatswich and the pan comes to a smooth stop in 1-2 secs. However no smooth pan with the Q400. I can still pan but only with immediate stops. Very unattractive. Perhaps Crosswind can look into this a bit deeper and advise us.