Like stated above, the D9 will let you survive. It is your choice to survive or play the odds, but when the odds are not in your favor, it would be foolish of you to not dive (or shallow climb), run, and reset your position. When you play online, get to a high altitude and hunt. If you get into a high energy turn fight, try to get in an advantageous position for maybe 2 turns, and if it is not working out for you, run and reset. It is tempting to keep turning with P51's, but if they have any clue how to fly you will eat it.