I have created a mission Two Spitfire Mk I nothing else.
The player plane is number two and the mission is very long but there isnothing else in the air.
First when I placed some, one overcast weather in the mission each time i TRIED TO LAUNCH IT CRASH OF THE GAME.
I remove the weather and the mission start without a problem, there one note the NPC plane do not warm up theyr engines.
Secondly afther some 20 minutes of play not a long time thus in midair the game crash again and Windows 7 x64 indicate that "launcher" has stop working and only solution is to go to the applications control panel and stop it.
long_patrol.zip
This my mission so you can all try it.
Win7 x64
Asus p6x58d
I7 975 3.75Ghz
System & game HDD 256Gb 10.000rpm.
12 Gb (6*2Gb) ddr3 1600Mhz memory
Geforce gtx580 1.5Gb
Trackir 5
Logitech G940.