Luggage in multi-connection intercontinental air travel

I did a similar connection three years ago although except for Heathrow each of my airports was a different one: My trip was FRA–LHR–YVR–YEG and back.

On your outbound flight, you will check in your bag in Brussels and not see it in London. You should go through the flight connections lanes at Heathrow and directly board your aeroplane to Canada.

Upon touching down on Canadian soil the first time in Calgary, you will have to first pass through Canadian immigration, then collect your bag and then potentially have it checked by a customs officer. (Incidentally, the first passport check seems to be only to determine whether additional questioning is required and thus whether the passenger needs to be separated after having collected their luggage — at least, that was my impression when I was asked to take the ‘other exit’ in Vancouver.) Assuming that you clear all of this, you then drop off or recheck your bag for the final, domestic leg of your flight.

On your return flight, this is different. Your only true domestic leg is the first one and there is no law in Europe stating that you must claim your luggage, pass through customs and immigration and then recheck them as is the case for Canada. Thus, your bags will be checked the entire distance through to Brussels. If all goes well, you will not see them once on that route. No rechecking is required anywhere.

You mention that you are worried about your luggage getting lost. While that is technically always a possibility it is just something that can happen and that you will have to live with. I personally have not had any luggage of mine get lost but I am not really a frequent air traveller. In any case, if your luggage is lost, it will be found by the airline or airport staff and forwarded to you as soon as possible. Since it would have been lost out of your control but in the airline’s or airport’s control, it is their responsibility to get it back.