Fast Forward (to descent/approach etc) / Time Shift Options

[PaulW1882]

Hi All

 

Does any know how the sim works out where to shift you to, when you use the fast forward to descent / approach options?

 

And wether it is possible to adjust these and set the distance and altitude from the airport that you fast forward to, yourself?

 

The reason I ask is that it all seems a bit random to me at the moment and sometimes I'm still hundreds of miles/over an hour away (when fast forward to descent) or almost on top of the runway (when fast forward to approach).

 

Any thought / help gratefully received !

 

Thanks

 

Paul