Samoa Air, which opened in 2012, asks passengers to declare their personal weight during booking, which is then charged per kilogram at a rate dependent on flight length. The customers will also be weighed at the check-in counter.
"The industry has this concept that all people throughout the world are the same size," Samoa Air chief executive Chris Langton said. "Aeroplanes always run on weight, irrespective of seats."
"There is no doubt in my mind that this is the concept of the future. This is the fairest way of you travelling with your family, or yourself."
Though the airline instituted the plan last November, it caught attention last week when the carrier began international flights to neighbouring American Samoa and coincided with the publication of a report by a Norwegian economist suggesting that airlines should charge obese passengers more.
The Pacific Islands contain some of the world's most prevalent countries for obesity, many ranking in the top 10, according to the World Health Organisation. Samoa is ranked number four, with 59.6% of the population considered obese, said the organisation's most recent 2008 report.
According to Samoa Air's latest schedule, the airline charges up to $0.57 per kilogram for domestic flights and $1.03 per kilogram for its only international flight to American Samoa. A 150kg person flying one-way internationally would be charged $154.50.
Children under 12 are charged 75% of the adult rate, with fares also based on weight. Any overweight baggage is calculated at the same rate as the passenger's personal weight.
The plan could actually prove cheaper in some cases, such as for families travelling with small children, and Langton said customer feedback has mainly been "amazingly positive". – Reuters