I know this has probably been asked before but do you have to be able to target lock to use Fire-Control System?

You don't need to have the target lock action on your ship in order to get a TL from Firecontrol system. You still have to abide by all other rules regarding target locks though. But I don't see any situation where you get to shot at some one without being in range to allso get a TL so it's kind of a moat point in this case.

the point of the question is if I am using a tie phantom with FCS, after his attack would he aquire a TL on that defender for the next round?

the point of the question is if I am using a tie phantom with FCS, after his attack would he aquire a TL on that defender for the next round?

The Phantom would get a target lock on the defender right after the attack is over. You can use this target lock the next round, or later if you prefer. The lock stays until you use it, just like a normal target lock.

Also attacker can only have one lock at a time. Unless he has Weapon Engineer then he can have two.

The restriction with FCS and Weapons Engineer is that one of the TLs must still be on the defender. If you manage to blow the target away, unfortunately, you end up with nothing.

The restriction with FCS and Weapons Engineer is that one of the TLs must still be on the defender. If you manage to blow the target away, unfortunately, you end up with nothing.

That's a nice problem to have.

The restriction with FCS and Weapons Engineer is that one of the TLs must still be on the defender. If you manage to blow the target away, unfortunately, you end up with nothing.

It would have been nice if FFG would have clearly worded the FAQ on this. The way it reads makes it seem like you only need to take the target lock on the defender first if it is a valid target.

Fire-Control System
If a ship equipped with Fire-Control System and Weapons Engineer attacks, that ship must acquire the first target lock on the defender (if able) before acquring a target lock on a second ship.

Yeah, that's right. You do need to be able to target lock the defender. FCS allows you to acquire a target lock on the ship you just shot at. The key wording for the combo is on the Weapons Engineer card: "When you acquire a target lock, you may lock onto 2 different ships". If there's no defender (because you've just blown him away), there's no defender to trigger FCS, and thus Weapons Engineer won't trigger either. You don't get a target lock on anything.