On Sat, 15 Nov 2003, M. Tettnanger wrote:

How many airports are there where you temporarily cross the
border during the approach?

Canadian ATC (Vancouver Terminal & others) control a fair size chunk of
airspace on the US side of the Washington-BC border, actually. Aircraft
going into Blaine or Bellingham are going to be talking to Canadian ATC
during approach, not American. Blaine is actually inside Abbotsford (CYXX)
extended control zone, which extends a couple of NM south of the actual
border. (CYXX itself is only a couple of NM north of the border...)

For example, I can fly from Victoria Int'l (CYYJ) to Abbotsford, cut the
'corner' of the border, actually make landfall south of Blaine in
Washington state, and never talk to anyone but Canadian ATC. Victoria
Tower, then Victoria Terminal, then Abbotsford Tower.

I've heard that around southern Ontario, ATC boundaries cross the border
all the time. Detroit ATC controls airpsace above Windsor, Ont, AFAIK.

Does each approach involve the foreign ATC agency, or
are there letters of agreement where, say, Brownsville
TX approach can control part of Mexico's airspace?

I assume it's all done by int'l letters of agreement.

Brian - PP-ASEL, Night -