Larry, Something similar happened to me: departing a small, uncontrolled airport right next to a medium-sized controlled airport, I called the controlled airport's tower for permission to transition, and received it. While transitioning, I got several calls of traffic (it's a busy area) and while avoiding those, I climbed a little more, and failed to note the overlay of a third large airport's wide-spread Class C airspace, whose floor was at the ceiling of the controlled airport's airspace.
Result: the tower I was transitioning told me to change frequency to the TRACON, who sent me to yet another frequency, who offered me the choice of "call this number when you land" or "talk to 'em now." Uh oh, I thought, but honestly couldn't think what I'd done wrong. I chose to "talk to 'em now" and went to yet another guy, who fairly kindly started off by telling me I wasn't in trouble, it wouldn't go beyond this, but here's what you did wrong. I imagine that spot has this happening fairly frequently, since the small airport I started from is actually inside a keyhole cutout in the big airport's overlay of Class C. Focusing on getting permission to transit the medium-sized controlled airport next door (their airspace starts almost immediately upon take-off from the small airport), it is easy to forget the Class C overlay and creep up into it. However, this only involved Class C, not Class B. Perhaps of comfort in your hypothetical situation, I talked about this at an EAA meeting and was later told by someone that the controllers have to tell you right then & there if you've goofed -- though I don't know for sure if that's true. Linda
