Is that what they call LOAL? Fire and fix?
In LOAL modes, for those missile which are capable of that, eg
Hellfire etc, the missile is launched at a trajectory without a
guaranteed lock. After launching, then the target is locked on. For
aircraft like the apache/longbow, it allows them to fire from
behind terrain masking, set the missile to clear a certain
altitude, before another aircraft locks on to the target.
This is generally bad news for those tanks with Active defense
systems, where they are able to detect radar , or laser designators
illuminating them. Reason is cos it really reduces their reaction
time.