Are there any aircraft used in part 121 (aka scheduled airline) operations that do not require a type rating to fly? Inspired by KeithS's question about ATPLs and category/class ratings, I figured I'd throw another type-rating/airline-operations puzzler at you: are there any aircraft currently in scheduled airline service (i.e. operated under part 121) which would not require a type rating to fly?  (I know part 135 operators often fly small aircraft due to the nature of their operation, with more intermittent or even on-demand service and the smaller locales they fly into.)
Cape air has a fleet of 83 Cessna 402s, some of which are involved in its Part 121 operation.