Originally Posted by
cmtlatitudes
AA'S Site (it's an award through OWE partner AA) indicated there's a terminal change at HEL, which made me more nervous also.
There is only one terminal at HEL.
For FCO-HEL-TOS, you will not go through security control or passport control, so basically no queues to slow you down. 50 minutes is plenty of time as long as the inbound flight is not delayed.