While we're all wracking our brains over the last few scheduling questions still unanswered, here's one that should be a gimme for many (and, admittedly, a head-scratcher for others).

What service in the 1960s was likely the shortest scheduled route ever operated in the US, possibly anywhere? Aircraft changed over the years, so airline -- including its 2-letter code -- and locations will suffice.

Just one hint: this segment was not offered for sale but could be deduced from the timetable.