Queenstown is surrounded by mountainous terrain and has no radar or runway lights.
CAA spokesman Bill Sommer said after the incident that airlines operating out of Queenstown must depart no later than 30 minutes before twilight as a precaution.
"If anything does happen they've got sufficient time to return to the airfield and land."
Is it a requirement in NZ to be able to return to the airfield of departure in the event of a problem? Or is there no EDTO Takeoff Adequate within range?