I can't quote the regulations on this, but I can tell you that at the training centre where I work, for an FAA initial type rating on a AW139, one of the sorties in the syllabus is flown single pilot.
Then in the check ride at the end there are particular elements (some of the approaches etc) which have to be completed without assistance if you have a copilot in with you for the check. I am not sure of the exact details, as i am not a TCE.
The A109 doesn't need a TR remember, as it is below the weight requirement under FAA rules.