Transit Time at Helsinki - 55min??

Have done transit < 1 hour several times through HEL, one of the most efficient airports in Europe. This is quicker (and might even give you time to pop into the Finnair lounge) if your transit is in the late evening after 10pm. I managed to squeeze in a quick visit to the nicer intl. (non-Schengen) lounge on my way back from Europe to HKG last month.

Agree. I frequently have 45 mins transit in HEL for BKK to LHR . You are not entering EU and gates are very close. I also transit to Dusseldorf which requires longer time as you have to formally enter EU and its quite a long walk to the Schengen departure gates. While the transit lounges (non-Schengen) are excellent if you have a time, the Schengen lounge is a zoo with never enough seats .

Same as above, done it several times, including one transfer for a plane leaving in 15mins, due to a late inbound plane from GVA and needing to go through passport control. I was travelling in J, but several Y passengers on the same flight managed to make it onboard no problems.

Finnair have short transfers down to a fine art, and my checked bags even made it on board.

In short, don't worry about it.

If you are flying the A350 from LHR, it might even be the same jet in Helsinki for your second flight. 55 minutes is no problem.

Did flights the other way around HKG-HEL-CPH and struggled as didn't realise there was a security check between F lounge and gate.

Made it but had to ask the customs guy if I could use the Euro entry line that had 5 people not 50