@Baron:
I found this interesting questions:
It happens that I forget this situation in this alternate Sub Warfare.
I would try to provide a specific rules when I will find if it falls in the sub alone category (historical POV: subs are not protecting scrambling planes) or the subs+warships (game mechanics POV: there is another different friendly unit in the SZ) category:What would happen in this situation.
Transports dont move but load and then unload from the same SZ.
A hostile submarine is available in the SZ as well as a friendly destroyer and some planes. ( so you can load )
Now defender scrambles 1 fighter and hits the destroyer.
Attacker kills the fighter but fails to destroy the sub.As we are in combat and the planes cant hit the sub and the sub cant hit the planes it is a stalemate there.
You cannot unload because there is still sea combat going on.
You cannot retreat because to retreat you have to move to a zone that your naval was comming from which is this SZ.Will the transports be defenseless ?? They cant run and the sub cant die.
Since it is clear that the defender have the choice to scramble planes or not, this situation will be put in the Subs with warships. I added the correction in the initial post.
I rationalize it this way: subs are mobilized to stop invasion and the amphib. assault so, instead fleeing any contact with ennemy’s ship, they are seeking them instead. Hence, no need to go on Air Search Patrol to find defending subs.
So, ennemy’s planes can destroy subs even if there is no DD on their side. See the opening post.