Shortest Mainline: BA
used to collect passengers for its YVR
747 flight by first flying SEA
. I've been on that one at least twice. Even shorter (but smaller) was Alaska Airline's JNU-GST flight on a 737-700. I think flight time was 18 min.
Longest Regional: Pilgrim used to fly a F-27 from JFK
. I can't remember the flight time, but it must have been 3+ hours. I suffered through that flight more times than I want to remember. In the early/mid 1980s Air Wisconsin offered ORD
-HVN service on a BAe-146. This too was 3+ hours and I suffered through it once before vowing to never do that again.