non-stop flight; direct flight
Refers to a flight that goes directly to the destination without intermediate stops. In Japanese, 直行便 often implies a non-stop service, though it can also be used for direct flights with no plane change.
The non-stop flight from Tokyo to London takes about 12 hours.
There is no direct flight, so you need to transfer once.
There's a direct flight from Tokyo to New York.
This time I took a direct flight to London.
There isn't yet a direct flight to that city.
I'm planning to go to Paris on a direct flight.
直行便 is the standard term for a non-stop flight, whereas 直通便 usually refers to a direct train or bus service that doesn't require transferring.
Compound of 直行 (direct, non-stop) and 便 (service, flight). The reading ちょっこう is a regular on'yomi combination.