Just die already! =o)

[SPEKTRE76]

Can anyone help this noob pilot?

I am flying in full simulation configuration. I'm using an X360 game pad with Xpadder activated and my keyboard.

• Plane: Spitfire MkIIa
  
• Enemy: He-111
  
• Location out in the channel

So, I line up behind this guy (AI) and I light up his engines but only one goes out. I destroy half his rudder and wing tips to kill his lift at high altitude. We were at 10K'ish? It works he slowly descends engine is still smoking and I can see some airframe under the skin. I kill all of his gunners. What they hell am I doing wrong? He will not burst into flames. I emptied my guns on him too. Should I just energy fight the big bombers and kill the pilots? I tried cutting his wings off too but it's a lot harder to do than I thought. Oh well any help will be apreciated!