New Zealand’s national airline is asking passengers to weigh themselves before they board international flights.

Air New Zealand has said it wants 10,000 passengers to step on the scales during a month-long survey so pilots can better know the weight and balance of their planes before they take off.

The airline has assured travellers that the numbers on the scales will not be visible and the data will remain anonymous even to staff.

The survey will be carried out until the end of June.