One question that I have always had is that when it comes to aircraft that have been modified, EC-135s, E-3s, AC-130s, Wedgetail....etc how do those radar and gun additions on the aircraft impact how they fly/handle...etc. Not sure if this has been asked before in this forum, but hoping some of the aircrew who have served on these platforms could shed some light.
The larger the protrusion, the less aerodynamic stable the aircraft becomes, especially if the protrusion is in front of the aero center (like a canard). Often they would add large fins or strakes to he back of the fuselage to help compensate.
Not all protrusions have the same impact. Objects with rounded trailing edges don't produce much lift or side force (depending on how they are oriented) and thus don't have much of an impact. The radome on the top of the forward fuselage of these aircraft has a relatively small impact on stability (I worked on all three):