Darn Head On's

[PantherAttack2]

First, what plane are you flying?

Second, I think trying to gain altitude is your best bet. Just don't start climbing when you see the enemy, start climbing before hand so you will have the advantage.

If there is no other way, you might be able to dodge the attacks by doing multiple barrel rolls when they are attacking you head on.

Other than that, I don't know. I personally think dropping down would be a bad idea, unless you have a great advantage in speed.