Your attack order gave the pilot two targets, and he followed his Weapons Release Authority (WRA) and released both CBUs on one tank troop, which has a "Missile Defense" estimate of 4 (see database). Once you watch the cool CBU graphics destroy one of the tank units, you are left with one tank unit alive and well. Time to strafe him.
- Select the aircraft Strike #3.
- Hit "CTRL + F9" and set the Weapon State RTB doctrine, in the right column, "No, aircraft do not RTB when weapon state is reached".
- Hit the "U" key. He was in an RTB state, so you have just unassigned him from that order.
- Hit "SHIFT + F1" and select the remaining tank unit.
- Strike #3 should already be selected, as is the only target. Click on the 20mm/85 Vulcan Burst in the suitable weapons column.
- Click on the bottom bar "Allocate all weapons of this type".
- Double check that all 5 available bursts (500 rounds of Vulcan cannon) are allocated and close the box.
- Manually order the aircraft to descend to 2,000 feet or lower and plot a course over the target.
You can also order the aircraft to conduct an automatic attack.