Panerai 580 help, what does the flyback hand do?

[RepPossessed]

I love this watch but my knowledge of Pams is about 2/100, i know enough that the flyback isnt gonna work.. so, what does the hand do thats normally used for it? from picture i have looked at its not static, and doesnt move with the seconds hand. is it a gmt hand?

any help would be great

 

[ALE7575]

Extracted from PAM GUIDE:


“Flyback” function, also known as the “retour en vol” or Taylor function, which is very simple to operate. The “Flyback” function is used while the chronograph is running (without stopping by pressing the chrono starting pusher) pressing the return to zero pusher, immediately returns the large blued centre hand to zero (we repeat: without having to stop it first) and the hand instantly starts again when the button is released. See Video:
http://www.youtube.com/watch?v=1G8CXrY0rz0&feature=related
The gens PAM “Flyback” feature this special technical function by means of special Panerai calibres.
The appearance of the “Flyback” function was catalyzed by the first watch with a separate chronograph button (the stop and reset functions were previously controlled by the winding-crown). This watch appeared in 1923 and was developed by Breitling_SA the chronographs have afterwards gained the form which they retained until today. In 1934 the Breitling chronographs received the second chronograph button with the function of returning the seconds hand to zero. Thus it became possible to measure short intervals of time using the add function. However the patent of the “Flyback” chronograph belongs to Longines with its first “Flyback” chronograph dating back to 1936.
This “Flyback” complication is impossible to get by the replicas and threfore they have False “Flyback” function. Moreover, the Display caseback denounces an, obviously, inaccurate movement.

ALE