Hong Kong CNN Business  — 

Doubts about the future of the Airbus A380 have grown after yet another airline canceled an order for the superjumbo jet.

Australia’s Qantas (QABSY) said Thursday that it had scrapped longstanding plans to buy eight more of the double-decker planes.

The A380 has been a major disappointment for Airbus (EADSF), racking up less than a quarter of the sales the European company forecast when it first introduced the giant jetliner more than a decade ago. The underwhelming demand has fueled questions about how long the manufacturer can justify continuing production of the iconic aircraft.

Airlines like Qantas have shifted their interest to lighter, more fuel efficient passenger jets.

“For Qantas, the A380 is the aircraft of the past and not its future,” said Ellis Taylor, Asia finance editor at aviation intelligence firm FlightGlobal.

Other airlines including Virgin Atlantic have ditched plans to buy the aircraft in the past year. Airbus now has only 79 firm orders for it, according to FlightGlobal data.

The program’s future could hinge on Dubai-based Emirates, the largest A380 operator with more than 100 of the aircraft in service. The Gulf carrier last year ordered a further 20 of the superjumbo jets, with the option to buy an additional 16 on top of that.

But Airbus said last month that it was renegotiating the deal with Emirates following reports that the airline was looking to switch its orders to the smaller and newer A350.

“Emirates switching all of its order would certainly be the death knell for the A380,” Taylor said.

Other potential customers for the aircraft include British Airways and Japan’s All Nippon Airways, but neither airline has committed to adding more A380s to its fleet.

“That makes it hard to see where more sales will come from in the near term,” said Taylor.

An Airbus spokesman on Thursday confirmed that Qantas had changed its order but didn’t comment on what it meant for the A380’s future.

Qantas said it’s in the process of upgrading its 12 existing A380s and planned to “operate the aircraft well into the future.”

Jethro Mullen contributed to this report.