Ryanair could be swapping low fares for no fares in a bid to boost passenger numbers.
Chief executive Michael O’Leary was reported as considering moving to no fares for many travellers.
In return, airports should share revenues from their retail operations, he argued.
He described airports as little more than “shopping malls” and insisted that they should pay airlines that bring in the greatest number of travellers.
His comments follow the publication of a report in September that showed airlines were inflating fares by £39 a passenger by selling extras on top of the basic fare.
The US research found that carriers made up to 43% of their income through shopping and additional fees, such as for seats with extra legroom and faster boarding.
Ryanair, which carried a record 114 million passengers in the past 12 months, has already offered fares as low as 1p.
O’Leary said that the airline made a loss on many promotional seats in Britain after paying £13 in Air Passenger Duty on every seat, The Times reported.
He said that Ryanair wanted to lower fares to nothing in five to ten years to boost its passenger numbers to 200 million.
This would increase returns on shopping, both at the airport and on aircraft, which is more profitable than the ticket price itself, he said.
He conceded that hubs such as Heathrow would not be able to share retail profits, but suggested that it was viable at smaller airports.
“I have this vision that in the next five to ten years that the air fares on Ryanair will be free, in which case the flights will be full and we will be making our money out of sharing the airport revenues,” he told the Airport Operators Association.
“I’m doing seat sales this week at £4 and I’m paying the £13 APD; I’m paying you to fly with me. Instead of promotional tickets being £9 or £5, they will be free.”