concur with crash O
work usally on f15 as well,
-Climb at minimum mach 0.85 (Dry power if you want to save fuel)
-Stay up there at mach 0.85/0.9
and last, very important, you can save good amount of fuel during the descent.
(If you fly at 40K, if you go idle, then -10° fly path, you will travel 40Nm)
With the mirage you can easily go to -7.5° for an economical descent.
Then if you fly at 50Kft, idle descent at -7.5° will make you travel 75 Nm idle wich is not negligible.
how to comput your time of descent?
easy way:
Take RTB heading, zoom in into HUD, when homebase hit the -7.5° line on hud just go idle and start descent (>300Kts) to put velocity vector on base...
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Math way:
Take your altitude, add half of it, that will give you your distance to base/navaids/tgt to start descent.
And by the way you can visually compute distance with hud using this methode
On this screen sochi is at : "alt+alt/2=distance" 11+5.5=16/17Nm