Hi bob_baer,
Hopefully the link below will be helpful if it's the RAF fighters you are referring to. For all RAF fighters, the mixture lever should be pulled all the way back in Full Rich position for take off, climbing, fighting, landing, and general sight seeing. The fully forward position of the mixture lever is Auto Lean, which is only used for level cruise at reduced boost and medium rpm settings to conserve fuel (rarely a concern in Cliffs of Dover -- the 109 pilots see to that).
Hope this helps!
http://forum.1cpublishing.eu/showpos...80&postcount=2