When you get the first banshee, instead of going to the
generator, fly to the locked door on the bridge and do the banshee trick to
get through. Once your through their will be no enemies anywhere and no
vehicles either. You can go for a long boring walk to the end of the map but
because there is no vehicles there will be no banshee to get to the end of
the level.
To get to the start of AoTCR on Two Betrayals, simply get the banshee at the
end of the map and fly up the bridge above. Go to the locked door with the
damaged wall around it and do the banshee trick to get through the door.The
texture mapping will disappear, keep going through the secret area to reach
the beginning of AoTCR. If you go to the same bridge and get through the
other locked door, you'll end up finding a lift inside.