Currently we have an all-or-nothing system, where unless the part is busted off its still operating normally.
I'm not sure how you'd coad it, but if you made small caliber guns do more damage, like 303s and 7mms (and 50cals even though they're large caliber) to control surfaces, or made the parts they hit lose a bit of lift, etc, the game might be a bit more fun and realistic. Historically small caliber guns shot down more fighters than cannon did. The guns shot away controls, messed up wings, or wounded the pilot. In AH you have to land 200 7mm rounds in a wing before anything falls off, and even then it's usually a flap or an aileron. It makes it almost useless in the world of cannon armed fighters ("almost"). I don't think they're being given their historical dues. Perhaps some way of "reducing" the effectiveness of parts based on damage. Take 5 7mm rounds in the inboard wing, and itll do nothing. Take 75 7mm rounds in the inboard wing, and you lose some lift on that wing (as opposed to nothing happening until the wing pops off).
This could also apply to the ailerons, elevators, and rudders.
This is related to the request for "in between damage", between "working" and "gone". It is also related to such requests as 2 stages of damage for certain objects, partially damaged and "gone". Also related to the flaps jam/flaps destroy request. Also related to the CTRL-D damage display using 2 colors (red for gone yellow for "damaged").