Whilst flying NW through DTW (a while back -- 3/30/04) I noticed that my flight to ORD (NW1505) was a continuation of a flight from, I beleive, a Canadian city.
As I had 3 hours to kill I did my share of wandering and gawking* I found NW1505 arriving at the other end of the concourse from where we were scheduled to depart (it arrived at A47 and we left from A17, IIRC).
I noted the number of the next flight departing from A47, went back to A17 and sure enough, the same flight was arriving at A17.
Both were DC9(-30s?), and each was operating the outbound portion of the other's inbound flight...
So the question is, and I know there must be a good reason for it, why did (as the flight doesn't seem to exist anymore) NW go through unloading/reloading cargo & checked luggage/make connecting pax trudge across the airport and all of the other stuff involved in a change of gauge just to get on another seemingly identical aircraft?. I could understand if they were going from a DC-9-30 to a 75 or something like that, but from a DC-9-30 to another DC-9-30? (And why not park them just a little bit closer together?)