Here's a good guide that I found that helped me through the missions. I hope this helped please let me know in the comments if you have any improvements or additions for my guide. Now trust me - fly straight into him kamikazi style! When you get to the base you may have to fire a few hellfire missiles to clear out what you are looking at (I did) and you will see the invincible helicopter that is the next mission objective. Fly straight for the small base ahead, watching out for the AA weaponry. When you are prompted to engage the HVT in the convoy - IGNORE it. On this mission destroy the drones and follow up by destroying the base as normal. He will stop at the edge of the level and just hover there if you survived flying round the base(I had R engine damage) then you can just sit back and take him out at your leisure. Stay well to the right of the base, keep low and head for the boundary of the level. He also conveniently flies over a heavily fortified base loaded with AA weaponry. Now as you are probably aware if you are shot down during this section it is mission failed because he gets away. If you are playing on training difficulty ( which is likely - I was) you will simply not have the speed to catch him. On this mission you will progress until you reach the mission objective to pursue the bomb carrier. Here are my guides for these two missions:
Unfortunately I don't have a walkthrough for the entire game but I particullarly struggled to complete the missions " A Damn Shame" and " Turkey Shoot"