Ok, try to beat this: 100% difficulty - 11 planes shot down!

   The mission review says  I only shot down 9 but if you watch the film,
   you can clearly see the  two  that  crashed into the  ground  after  I
   shot them - I count that as a  kill, 'cause  there  was  no  one  else
   around to do the dirty work for me!  I was running low on bullets...

   I made the mistake of dropping my external fuel tank too  early  -  so
   I had to bail out from lack of fuel at the  end  -  but  I  landed  in
   friendly territory so that's ok! (hey, I lived didn't I?)

   If you are going to play the mission, make sure you set the difficulty
   level at the start.  I had to set it to 100% while I was still on  the
   runway - if you don't set it, I think  you'll  end  up   with  34%  or
   something and once you begin combat, you can't change it. You can tell
   when I changed the skill level because there is a pause when I  am  on
   the starting runway.