Have you ever wanted to shoot some one down in a jiff, or let them live then kill there tank, read on
Letting them live: You put holes in the wings, cut there feathers, let them burn, this is the easiest place to shoot and hit, due to size, shooting there wings is far more likely for them to get hit, so shoot for the wings, if you're chivalrous, they will survive this, and hopefully if they have a soul, they wont shoot you in the chute, then you shoot up there tank, cause we ant wanting not of that.

Jiffy Dead: shoot the fuselage (body of plane, that contains fuel, pilot ect), it will kill then no chute at all. I painless death, hopefully.