When I lived in Connecticut, I used to frequently drive down to the Washington D.C./Baltimore area and "DO" the 3 airports. DCA was my favorite, especially hanging out at Gravely Point. Now this was 1992-1995. The shuttles were all 727 back, then and the majors (AA,UA,DL,CO,TW,NW,US flew plenty of Boeing 727 aircraft back then. Over the years, the number has drastically decreased. When I visited last Labor Day weekend, there were only about 10 727 daily. All 4 majors that still operated 727, flew them into DCA(AA,UA,DL,NW). UA & AA no longer fly the beautiful beast, and though NW still flies them, they do not to DCA. This leaves on DL, with 2 flights into DCA. This of course will end soon.
Now one might think: "Hey the 727 will end everywhere, whats special about DCA?" Well for one thing, other airports have cargo airlines which still fly the 727. But DCA has no cargo flights, so when the last pax flights go, that's it!
Secondly, back in the mid 70's to early 80's, DCA was literally NOTHIN' BUT 727s!!!
Look at what the airlines were flying in there: (100 & 200 unless noted)
Continental 727-actually they might have been at IAD
Delta 727, DC-9
Eastern 727, DC-9
National 727 & later Pan Am 727
Allegeny 727,DC-9 & smaller
Notice, for 5 carriers, it was nothin' BUT 727.
But the end will come soon.