"Bill" wrote in message
...
On Thu, 02 Jan 2014 07:49:00 +0800, Anonymous
wrote:

You can always stop and ask, but if your bag isn't checked through,
you need to pick it up, which in this case means entering the UK at
this point (and I'm assuming flying domestically to complete your
travel?)

You cannot trust airline staff to know the answer to this.

In traveling EU to US via Canada, I was told that I must collect my
check-on luggage in the *first* US stop, and re-check it. (this
sounded reasonable because i've had to do that in the past). But it
was bad info. *Two* staff members in two different cities along the
way gave these same wrong instructions.

I went to collect my bag, but it never appeared. I was forced to run,
stand in line, and re-enter the secured area to catch the next flight.
The bag was ultimately checked through the first city traversed in the
destination country, and arrived at my destination. I was needlessly
advised to go through TSA, and risk missing a connection.

Travelers need a more certain way of knowing, without relying on
airline staff. Sometimes there is a customs "pre-screening" check,
and sometimes not. Sometimes there are multiple international
airports (read: airports with customs). In some cases there is a
customs service for the destination country doing a full customs
process on the soil of a foreign country.

How can we know? There must be an algorithm.

As a general rule when your bags are checked in they are 'tagged'
with an international style tag. This has the trigraphs of any
airports transited and the final airport destination marked on it.

The check-in staff will also give you a stick on luggage claim
sticker, usually affixed to the small folder your boarding cards come
in.

Always check your paperwork and always make sure, from the people who
affix the tags to your baggage, where you will be collecting it.

Doesn't work like that when you are flying to a point behind a US gateway.
For instance London/Chicago/Denver will have a tag saying LHR/ORD/DEN but
you have to collect the bag at ORD, go through immigration then customs and,
as you exit customs recheck the bag with your domestic carrier.

But "Anonymous" was (if I understand him correctly) doing something like
London/Toronto/Denver/Butte. He says 2 airline staff told him to collect
the bag at Denver (1st US point) then recheck for Butte but his bag never
appeared at Denver and it appeared at Butte.

I think I understand what happened but it intrigues me a bit.

Toronto has airside transit (in other words you don't need to enter Canada
to catch another international flight). It also hosts US immigration.
What happens is you get off your plane from Europe, go to the US departure
area and en-route you go through US immigration (while still in Canada).
However, you don't go through US customs as far as I can see from the
airport website. In any case, when the plane arrives at Denver it is
treated by the US as coming from a US point (because immigration has been
completed) so there is no need for the pax to go through customs (or
immigration) and the bag can continue as an interline bag from one plane to
the next at Denver.

Something doesn't feel right in my explanation but based on what I see on
the Toronto Pearson airport website
http://www.torontopearson.com/Connecting.aspx that seems to be the process.