FARNBOROUGH—Emirates president Tim Clark has again called on Airbus to develop an aircraft larger than the A350.

With large-capacity widebodies such as the A380, A340-600 and Boeing 747-400 out of production, rising passenger numbers demand a new twin-aisle design, Clark said at the Airline Leaders Summit on the sidelines of the Farnborough Airshow.

“I’m hoping Airbus will be a little bit braver,” he said.

Airbus and Boeing seem largely focused on narrowbodies, to the exclusion of new widebody designs, he said. “To say it’s all about the A320/321 and the MAX, in my view, is not that smart.”

IATA director general Willie Walsh, who also spoke at the summit, agreed there were parts of the world where a 350-seat, four-class aircraft would be needed in future.

The two executives also took shots at Airbus and Boeing over how they leverage their duopoly.

“We’re customers, and I don’t feel we’re always treated as customers,” Walsh said, noting that Bombardier built “a good aeroplane” with the CSeries, but was unable to compete against Airbus and Boeing. Ultimately, Airbus bought the CSeries program and renamed the aircraft the A220, which is selling well as an Airbus.

Walsh said that China’s COMAC C919 would eventually become a competitor, “but I think it’s a long way away.” And while China could design airframes satisfactorily, engine development remained a problem, which meant that for the foreseeable future, China would continue to depend on western engine manufacturers.