this may not be accurate, but i think its how this works
when offline, you have to hit a drone a certain number of times for it to go down- 7.62 to 30mm do the same damage. if you take out a wing, the cpu does not respond to this by making the plane go down. the reason it happens online is because the players are using their own cpu, therefore it responds to it's own flight axis. if you did this offline, many systems would simply crash