The variety and availability of missions is dictated by the estimated difficulty rating
of that mission and your current pilot ranking. The theory being that rookie pilots are
not assigned excessively dangerous missions.
The mission difficulty tree looks something like this:
Rank |
Min
Difficulty |
Lieutenant
Captain
Major
Lt Colonel
Colonel |
6
7
8
9
10 |
Therefore any mission with a difficulty over 7 is unavailable to Lieutenants and
Captains.
The difficulty rating is rated by type, length of exposure behind enemy lines and
number of estimated enemy contacts.