CTA.....Ground strafe kill is "Ground Target " kill ??

[Robotic Pope]

Ground Target = Bunker/Ship

The two I-16 ground target weapon unlocks are not plane specific, so you unlocked them the first ever two times you destoyed a ground target in Birds of Prey online.

The absolute best way is to get a friend in a B-17 with 2000lbers to drop two bombs on each target, follow behind him and attack the same target and you will find one bomb or a salvo of rockets will finish the job and the target will explode, move on to the next and repeat. With some B-17 help I raced through the La-7, P-51D and IL-2m weapons unlocks (and thats pre patch unlock amounts)