I flew by Ryanair from Santiago to London in June this year. The Ryanair ticketing site will give you their dimensions and weight restrictions which may well differ from that of other airlines (certainly different from Virgin Atlantic). They are very strict and will let you through the check in desk, security etc all the way to the departure lounge where they will bring round their measuring container and check EVERYONES luggage. Ryanair departs from Santiago airport (Lavacolla) airport, which is about half an hour bus ride from the city, and buses run every half hour from the city. Check with the tourist offices in Rua Vilar (very close to the cathedral) for departure points and times. I checked in my bags and my poles when disassembled fit in my 34 litre backpack.