Original Message

I do believe that when it's time to move on , you just know based on your own personal situation , not just hours of flight time or years of service but more just a feeling of purpose and life situation. This would apply to any job or profession . 
It's  so personal that no one can tell you when it's time , you just know when it is.

what ever you decide it will be the correct decision at that moment in time , wish you all the best for what ever you decide .