i have round trip tickets from usa to spain. my layover is in london. i want to start my trip in london and just make my way down to spain to pick up my return flight. the problem is my backpack. i'm pretty sure it will be too big for carry on. if i check it how the hell can i get my hands on it in london before it gets automatically placed on my spanish flight? does anybody have experience with this? any bigger problems about this plan that i don't see? how many licks to the center of a tootsie pop?
In a nutshell: You can't. If your flight is to Spain, then that's where your bag is going to end up, my friend. If you really want to start your trip in London, try changing your ticket instead. I guarantee the cost to change your ticket will be easier to bear than the nightmare of landing in the UK with your backpack in Spain. Plus airlines tend to get real unhappy when people don't show up for their connecting flights.
but i'm Rick James bitch! damnit that sucks. what if i manage to get a pack that will fit as a carry on? what do you mean about the airlines getting unhappy about not showing up for a connecting flight? what if i gave them a heads up on not boarding the flight? stupid airlines. thanks
You'll have to call the airline and cancel the London-Spain portion of your itinerary. It shouldn't cost you anything, as you're freeing up a seat for them. The reason they don't like it when people don't show up for scheduled legs of flights is that it wastes a seat, and you could feasibly put a bomb in your luggage that will blow up on the second leg. The latter is, of course, pretty damn unlikely, but that's one of the airline scenarios out there.
As far as backpacks that will fit as a carry-on, get something that's 51 linear inches (H+W+D) or less, and you're set.
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The cabin baggage allowance for economy class is 6kg.
Of course, I've *never* had my carry-ons weighed, so there's always that But if you're going to cancel the Spain leg anyway, you can go ahead and check your luggage with no worries. Just make sure they tag it with an LHR luggage tag when they check it in!
__________________ ¿Donde esta Omid? Omi-san wa doko desuka? Ou est Omid? Wo ist Omid?
It's unfortunate that your trip is already booked.
Next time, you might just book a ticket that arrives and departs from two different cities. It is what I will be doing when I (hope to) go to Europe this winter...I will be flying into Helsinki, and flying back to the US from London. It's actually working out cheaper than a roundtrip flight to Helsinki would cost me.
As Omi said, call the airline and ask them if it would be possible to cancel the London-Spain leg of your trip.
If you really want to start your trip in London, try changing your ticket instead. I guarantee the cost to change your ticket will be easier to bear than the nightmare of landing in the UK with your backpack in Spain. Plus airlines tend to get real unhappy when people don't show up for their connecting flights. 
But if you're going to cancel the Spain leg anyway, you can go ahead and check your luggage with no worries. Just make sure they tag it with an LHR luggage tag when they check it in!
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