If this has been addressed before i have missed it and sorry. But would like to know if his ability does trigger this on both attacks. Thanks.

Yes.

If an upgrade is not intended to activate during multiple attacks, it will say so, either by saying "Once per round", or by the expenditure of a token.

That being said, Fire Control System is traditionally stronger on Corran. It has a higher damage ceiling.

Advanced Sensors are also a great option for a more survivable, maneuverable Corran.

Accuracy Corrector is generally not worth its cost on a ship with 3 attack dice. It's only a consistently good buy on TIE Advanced currently.

Thank you both for your input. I thought that maybe adding ac would add a guaranteed 2 damage for corran. but i do see the point that has been made.

I was thinking that accuracy corrector might be a decent idea for when the red dice went bad. That is why i was wondering.

Accuracy Corrector is generally not worth its cost on a ship with 3 attack dice.

This isn't true, actually. Accuracy Corrector keeps your attack results moderately high, regardless of whether you're able to modify your red dice. So it's an escape route from the action economy, like PTL: if I have an Accuracy Corrector, I can make a solid attack and barrel roll, or make a solid attack and evade. If I have two attacks per round (like Corran sometimes does), I can modify both of them without an action, which is even better.

I'm not sure it's the best system for Corran, but whether or not it's worth its price on a ship with 3 Attack depends entirely on the ship, the action bar, and the playstyle.

I could see Horn AC working well against a fast list (A-Wings, Interceptors) after your double tap they should hopefully be dead. But if not your TL might not be on your next target. Overall though I prefer FCS on Horn.