(Reuters) - Airbus is considering doing away with one of the hallmarks of its A380 superjumbo, a “grand staircase” echoing the era of cruise ships, as it looks to revive sales of the world’s largest airliner, industry sources said.

FILE PHOTO: Interior view shows the stairs between two decks in the Airbus A380 at Frankfurt Airport, Germany, March 22, 2007. REUTERS/Alex Grimm/File Photo

The idea of a slimmed down staircase, as well as adding fuel-saving wingtips, is aimed at lowering the huge double-decker’s operating costs and boosting its fuel efficiency.

The provisionally dubbed A380-Plus makeover would add 40-50 seats to increase the standard interior’s capacity to more than 600 seats which would help airlines reduce their costs per passenger.

To make room for those extra passengers, the A380 would do away with the double staircase at the front of the plane in favor of something more compact. The narrower spiral staircase at the back would also be modified.

Airbus officials declined to comment on the plans, which have yet to be finalised and approved.

“Airbus is always studying opportunities to improve our aircraft,” a spokesman said.

The sweeping staircase is one of the first features passengers see on boarding an A380 and captured attention when the A380 was first rolled out as a ‘cruise ship of the skies’ in 2005.

However, sales have fallen in recent years due to advances in smaller twin-engined jets, which cost less to fly and maintain.

To help on the A380, the addition of vertical wingtips, more typically seen on smaller narrow-body jets, would cut fuel consumption by reducing drag.

The sources, speaking on condition of anonymity, said the makeover would improve fuel efficiency by around two percent.

They said the changes may also be available as retrofits to existing A380s, but that this had not yet been decided.

The design changes would add about three tonnes to the A380’s maximum take-off weight, leaving more room for payload or fuel.

Airbus recently shelved plans for a bolder upgrade of the A380 involving new engines due to cost, and announced plans to cut output to one a month due to poor sales.

Beyond the new tweaks, the health of the program depends on getting costs low enough so that Airbus can keep output ticking over at 12 a year without losing money, while it waits for what it hopes will be a rise in demand as air travel grows.

“The time will come for the A380,” Airbus sales chief John Leahy told the ISTAT Americas air finance conference this week.

Airbus was due to unveil a dedicated online booking system for A380 flights at a Berlin show on Wednesday.

The European company’s U.S. rival Boeing argues the time for very large four-engined jets, such as the A380 and its own slow-selling 747-8, is ending.

In the short term, Airbus faces another challenge: helping investors find homes for five A380s due to be released by Singapore Airlines after their lease expires.

So far there is no second-hand market for the jets, which entered service in 2007, and several ISTAT delegates said it would not be easy to find takers due in part to the high costs of converting the interiors to suit the needs of a new airline.