re sitting on the runway, this happened to me on Delta at MCO a few years ago. It was evening, the plane was late incoming, and I, even though I'm not a pilot, knew that the crew was about to exceed their permitted work time before they go back to LGA. They didn't tell us anything. Don't know why. We hadn't left the gate, but they still didn't let us off for a few hours, until the permitted time had expired.