The lighting is on your plane only. If you fire your guns, the plane in tight formation with you will not get illuminated.
I like other flight simulations where the whole environment get's illuminated, like an explosion lighting the bottom of the clouds.
In AH this effect is not visible past 300y or so. It's unfortunate as it cannot be used to see when someone is shooting at you. I could be usefull when eny is using no tracers, especially on FPs and the maned invisible ack.
Slowly ... AH is improving.