A new industry study finds that 47 US representative airlines collected more than $21bn in add-on fees last year, about 35 per cent above their receipts for the same services in 2009.

But some of the airlines say the extra revenue does not cover the higher operating costs - especially fuel.

They say the impact of events like the Iceland volcanic eruption and the Japanese tsunami have also added to a higher price tag of a ticket.

The international air transport association has forecast that its member airlines will post $8.6bn in profit this year, but that is just half what they earned last year.

Al Jazeera's Tom Ackerman reports from Washington.

Source: Al Jazeera