I don't fly often (8 RT flights foreign & domestic in 30 years). I have always flown direct. I am trying to fly from Boston to London in September and discovered that a flight with a short layover (Ireland or Iceland, an hour to an hour and a half) is acceptable, especially considering the cost savings (times two). Here's my silly question. What happens when I arrive in Iceland or Ireland? Do I have to retrieve my luggage and recheck it? If not, is this a greater opportunity for my bag to become lost? Do I stay on the plane? Could someone explain the logistics of what I might expect? Thanks so much.
Your first flight will usually check your bags all the way through to your final destination. Always keep your luggage tag receipts. If you ask nicely, most of the time the gate personnel will check the tracking numbers on the tickets to see if your bags made the connection.
To answer the second part of your question, it is very unlikely you will stay on the same plane (even if you did, you'd have to get off so they can clean it). After you arrive in Iceland or Ireland, you will exit the plane and change gates. Depending on the airport, there may be security checks between gates, or at the gate you are changing to. If you are very polite asking, the flight crew may be able to tell you what your next gate will be. If they don't know, after you get off the plane, find the nearest screens/information display that lists the departing flights and their gates - in your case, look for the airline you're flying, London, and the time your next flight leaves, and find the gate number. Follow the signage (usually pretty good in most airports) to your gate. Don't delay, if you only have an hour or 1.5 hours you will not want to waste ANY time (that is a very short layover). If you are flying the same airline all the way, make sure to ask that they check you through so you have boarding passes for your second flight. If that isn't possible, be sure to ask what the process is to get a seating assignment at the layover airport.