On my date of interest, AY seems to be holding back business class award inventory on the A350 to LHR only for connecting passengers from outside Finland (not for ex-Finland or direct HEL departures). With that in mind, I'm considering positioning to TLL.

Can anyone describe the AY HEL-TLL arrival process in Tallinn? Would I enter the airside terminal and be able to immediately board the same ATR-72 back to HEL? Or would I be dumped out landside and have to re-clear security? Since all intra-Schengen, I wouldn't expect customs/immigration...

To be fair, this is complicated by my itinerary being TLL-HEL-LHR-USA, so I would also need to be able to check in electronically. Otherwise, if forced to check in at the counter, would need to allow time for that, and also either be forced to bring along my baggage (instead of leaving at HEL airport hotel) or have to explain why/how I'm traveling to the USA with no baggage.