Term to differentiate between a flight and a flight instance? What's a term to differentiate between a flight schedule (QF 72) and a particular instance of that flight schedule (QF 72 departing on July 25)? 

For example, I might ask "Which flight are you taking", and you might reply "QF 72". What I really meant was "Which scheduled instance of QF 72 are you taking?"

The flight schedule and a specific instance of that flight schedule are both referred to as a "flight". What are the terms that more precisely differentiate between these two concepts?
You might say "the QF 72 service between Singapore and Perth" for the flight schedule, and "the QF 72 flight on July 25" for a particular instance of the flight.

The term service used in this way is seen more often in other transportation sectors such as bus and train. But it can also apply to scheduled air services.