Originally Posted by
CX828
... T3 is normally very quick as the number of US departures is smaller + most planes are just regional jets.
Actually the volume of big jets bound to the USA from T3 is huge. Charters on Westjet make up a lot of this. Such flights are invariably scheduled early morning to inconvenience pax as much as possible. Hence the massive morning kettle call. Scheduled flights to New York and Chicago, on legacy carriers, are small potatoes.