Would be nice.
This has been already discussed... In fact, I was basically asking for the same thing. Apparently, it would be pretty strenuous on the PC it's running on.
Huh. That makes sense.
Just to be correct; Howitzers shoot 'straight' (with arc). What you are suggesting is a Mortar / Artillery; a.k.a. Indirect fire.
Also basic ballistic calculations are trivial, even 1000's of them per second.
Its basically what computers were INVENTED to do. ;)
flaks and ventral/dorsal turrets exist already, I see no point in a curved projectile
Looking back on it, a mortar isn't even important for the game. It only makes sense when cover is in play, which doesn't exist in Airships.
Actually, mortars can be used for to be effective againts non-moving targets. It may be a cheaper, less effective alternative for aerial torpedoes.