Waiting at and flying from Pittsburgh

The airport at Pittsburgh is huge but not many gates are used... Talking to someone he said that the reason is that US Airways used it as a hub and the city built a $1 billion terminal with more tahn a 100 gates to suit its needs as its largest hub.... The May 1995 timetable shows USAir nonstops from Pittsburgh to 91 airports, plus 28 more on USAir Express. By the late 1990s growth had leveled off, with USAir (now American Airlines) concentrating on expanding at Philadelphia and Charlotte as it hubs. These are the jets I managed to get while waiting my flight...

Delta Airlines' Bombardier CL-600 N349PQ at Pittsburgh on 28 September 2016

Delta Airlines' Boeing 737-800 N371DA at Pittsburgh on 28 September 2016

Delta Airlines' Embraer ERJ-170 N871RW at Pittsburgh on 28 September 2016

Southwest Airlines' Boeing 737-700 N481WN at Pittsburgh on 28 September 2016

Flying in a United Airline's Boeing 737-900 from Pittsburgh to Chicago...  I have never got to fly on a 737-600!