This is covered by the FAQ and a step by step run through is included.
Quote:
Q: A formations of Ork Fighta Bommers attacks a formation that has a Hydra attached to it. The Fighta Bommers are also intercepted by two Thunderbolts. What is the order of fire for the Thunderbolts, Hydras, Fighta Bommers AA and Fighta Bommers ground attack?
A: Each formation is allowed to make its Flak attacks after each new air unit has finished its approach move. The attacks would then be resolved in the reverse order that they were initiated following the rule of approach, flak, attack. So the Fighta Bommers would get a Flak attack at the end of the Thunderbolts approach move, the Thunderbolts would get their air attack, the remaining Fighta Bommers would then take fire from the Hydras and then the Fighta Bommers would finish their ground attack.
The order of aircraft and flack attacks is
summarised in the following table:
• 1. Attacking air units activate and move
into position.
• 2. Defending player may "un-CAP" up to
one aircraft formation on patrol and
move it into position.
• 3. Attacker's unit ground flak fires at
CAP (if applicable).
• 4. Attacking aircrafts' defensive AA fires
(i.e. not just ground flak)
• 5. Defender's ground flak fires at
attacking air units (if applicable).
• 6. CAP formation fires at attacking air
units (if applicable).
• 7. Attacking air units perform ground
attack or assault.
Only Formations already on CAP can interupt an opponents ground attack action to try to intercept, you cannot attempt to go on CAP as part of your opponents action. If you have no formations already on CAP you cannot intercept.
Also unless you are using house rules this following cannot be done (cannot CAP a CAP)
Quote:
The playing making the ground attack may also declare that their CAP is intercepting the enemy interceptors, so this takes place first, followed by the intercepting unit from the enemy defenders, followed by Flack attacks from both sides, and then the bombing run is carried out.
Formations on CAP can only react to a ground attack action, coming of CAP to intercept other interceptors is not reacting to a ground attack action