We have it at our Border's in New Orleans, I've also seen it, in fact, at a Books-A-Million in, of all places, the airliner mecca of Monroe, Louisiana.
It seems to me that Border's usually gets the issue in the middle of the month (eg. March came in about March 15th). Of course, by then in the UK, they're already looking at the April issue.
Tom in NO (at MSY)
P.S. An "Airliners" magazine question: I was just out of town, and lost track of issue dates. Is the May/June issue out yet?
"The criminal ineptitude makes you furious"-Bruce Springsteen, after seeing firsthand the damage from Hurricane Katrina