In case any transfer passengers are reading this, HEL is unique in that it doesn't run you through any security clearance if you arrive and are just connecting to another flight in HEL. Every other airport I've flown through, from LHR to FRA, will still run you through a security check before you can board your next flight.

Of course this probably depends on where you are connecting from, from some places I'm sure the security check will still apply. But when flying WAW-HEL-SIN I only have to go through security once in WAW and that's it. ^