Board Thread:General Discussion/@comment-3522837-20150208144015/@comment-25045164-20150603084708

You can use either A2A or A2G lock-on speed part but not both at once. Regardless of which part is used, the speed is enhanced when locking on both targets. It gives only 10% boost average so time taken to have all 12 missiles locked is 3.2-3.4 seconds, a drop from 3.5-3.7 seconds when not equipped (data from test flight).