Excellent! Thank you DKoor I upped the carriers speed to 60 km/h (from 30hm/h) and now they can take off without crashing, although the planes on the right still have their wings clip through the control tower :S.

Seems a bit silly for the game to generate a mission where the planes you're supposed to escort can't take off

I noticed the same problem in the stock Pacific Dgen campaigns (in the Tarawa and Japan subcampaigns). On both maps the speed of the carriers is to slow. It is an old problem, unfortunatly it was never fixed because of the lack of support for Dgen.
The best way to fix it is to open the Japan1Red and TarawaRed template files (look in the DGen folder) in FMB and increase the speed of the carriers.