There's a world of difference between qualified airline pilots and copilots 'in reserve' and qualified railroad crews 'in reserve'.
First and foremost, the pilot has to be qualified to fly that particular model aircraft. I once sat beside a uniformed Northwest Airlines pilot that had a Boeing 727 manual he was busily studying. He told me that all pilots get tested every 6 months on every type of aircraft they are qualified to fly and his test for the 727 was the next day. In other words, a 727 pilot is NOT automatically qualified to fly a 757. I don't think pilots have to be 'qualified' to fly into an airport they've never flown into previously. But there are airports, such as WAS (DCA?) (aka Reagan Airport) that I certainly would not want a pilot unfamiliar with that airport flying ME into the place!
On the other hand, an engineer must be qualified to run on the route before being allowed to do so. An engineer at NYP, for example, might be qualified to take any non-Acela train to WAS or BOS. But if he/she has never 'qualified' on the route to ALB, they cannot take the engineers' seat! Qualification on each route entails learning the characteristics 'first hand' including speed limits, permanent speed restrictions, stations, grade crossings, signals, hills, valleys, etc.