Originally Posted by
milepig
Happens more than you think, usually when a flight gets off schedule (like the above situation). An example of something that might be more typical would be when a flight from, let's say SFO-ORD-LHR (with a plane change at ORD) gets behind on the SFO-ORD leg, and the ORD-LHR (with the same flight number) takes off before the SFO-ORD lands. I don't know what every airline does, but UA tacks a 9 onto the front of the second flight - so in the example I use SFO-ORD would be xxx and ORD-LHR sould be 9xxx.
Actually, they refer to this as a "Stubbed Flight". Delta adds a 9 to the front of the flight number of the second flight. Other airlines have different numbering conventions. I have actually seen the words "Stubbed Flight" on the gate display. I have no idea where the expression "Stubbed" comes from. Does anyone know?