For the bombing run with dive bombers they would get shot at with AA before releasing their bombs. If it were a torpedo bomber outside of the 4 inch AA range then they wouldn't get shot.
I realise this may be a slightly stupid question but where in the rules does it say this? It's how I've always played it, but I've never been able to see where in the book it says when you are able to make defensive attacks - it doesn't seem to be in the defensive ordnance section!
Just to further clarify, the torpedoes from a torpedo bomber SAS have a max range of 4" (pg. 186). So, this means that the target model will get to make an Aggressive Counter Attack with Ack-Ack (see pg. 125), since the range for Aggressive Counter Attacks against SAS is normally 4" (see pg 185). It also means that the target will be less likely to have linked AA from its squadron mates since any supporting models will also need to be within 4" of the attacking SAS, and with some careful placement on the part of the player making the attack with the SAS, they can avoid being within 4" of more than one model in the target squadron.
So, the sequence of events for a Torpedo Bomber SAS attack should be as follows:
1. Player A activates their TB SAS and moves it to within 4" of one of Player B's naval models.
2. Player A declares an Attack Run on Player B's Model.
3. Player B's model gets to make an Aggressive Counter Attack with Ack-Ack against Player A's torpedo bombers. If Player B's model has any ships in its squadron that are also within 4" of the attacking SAS, they can link with the targetd model to boost its Ack-Ack defenses. Applicable MARs apply. Any SAWs that Player B destroys with his Aggressive Counter Attack are removed from Player A's SAS.
4. The surviving SAW in Player A's Torpedo Bomber SAS now execute their attack run.
5. Player B's model gets to make a Defensive Counter Attack against the incoming torpedoes using Concussion Charges.
6. The remaining hits from the torpedoes are applied to Player B's model, rolling for crits as necesary.