Originally Posted by ACMS
It's not unusual to hear foreign carriers requesting taxy clearance in HKG while the ground crew are still at the nosewheel.
At my former workplace, sometimes this was done to beat curfew. Sometimes technical delays brought the departure time too close to curfew for comfort. ATC could not give the aircraft clearance to takeoff if
taxy clearance hadn't been given by a certain time before curfew. The engineers/pusback personnel understood the concept, but one or two flight crews had difficulty understanding this (or perhaps didn't feel comfortable bypassing normal procedures) and we had to tow the aircraft back to the gate for an overnight stopover.