This may be related to sam007's question. I use the FlightAware web site. I read the recent reviews of the FlightAware App and see there are a lot of negatives.

One bit of information I've been unable to find on the web interface is the "filed flight plan".

For example, I was tracking a flight last week, that had departed from the gate, but was held on the ground for over 2 hours. The flight shows up on the airport page under "Scheduled Departures", which only shows the gate departure time. When the flight eventually takes off it then appears in the upper list Departures with the actual takeoff time. During the 2 hours, there was no information other than the gate departure time.

Presumably somebody has a schedule for when a given flight will take off, so they can order the aircraft on the ground and in the air. Is there any type of flight plan that would give a clue when the flight is actually scheduled for takeoff? Can that be access through FlightAware or other web sites?