A Samoan airline that says it is the world's first carrier to charge passengers by their weight rather than per seat has defended the plan as the fairest way to fly.



The airline defended its decision by saying that in some cases flight costs ended up cheaper than conventional tickets.



"The industry has this concept that all people throughout the world are the same size," Samoa Air CEO Chris Langton told the Reuters news agency on Wednesday. "Aeroplanes always run on weight, irrespective of seats."



Though the airline instituted the plan last November, it caught attention last week when the carrier began international

flights to neighbouring American Samoa.



'Concept of the future'



Samoa Air, which opened in 2012, asks passengers to declare their personal weight during booking, which is then charged per kg (2.2 lb) at a rate dependent on flight length.

"People who are up around 200kg recognise ... they're paying [for] 200kg, so they deserve to get 200kg of comfort" - Chris Langton, Samoa Air CEO



The customers will also be weighed at the check-in counter.



"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, " Langton said.



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 (WHO).



Samoa is ranked number four, with 59.6 percent of the population considered obese, said the most recent WHO report released in 2008.



According to Samoa Air's latest schedule, the airline charges up to WS $1.32 ($0.57) per kg for domestic flights and

WS $2.40 ($1.03) per kg for its only international flight to American Samoa, around 402km (250 miles). A 150kg person

flying one-way internationally would be charged $154.50.



Children under 12 are charged 75 percent 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".



"When the initial shock has worn off, there's been nothing but support," Langton said. "People who are up around 200kg

recognise...they're paying [for] 200kg, so they deserve to get 200kg of comfort," he added.