Boeing has powered up its newest aircraft, the 777X, which will be capable of flying from Los Angeles to Perth as it prepares for the super jet’s rollout early next year.

The power-up process enables the company to test every system on the plane to ensure that when it is unveiled, it is fully functional.

Boeing is coy about announcing the rollout date but industry sources said it was expected to be mid-February.

Boeing is building two models of the 777X family — the 400-seat -9, which will be the first to be unveiled, and the longer range -8, which can seat 350 passengers and has a range capability of more than 17,220 km.

The 777X features a 3m folding wing-tip. It is this model that Qantas and Air New Zealand are evaluating, with decisions expected early next year.

The driving force behind the 777X is Emirates president Sir Tim Clark, whose airline is the lead buyer with an order for 150.

Sir Tim describes the 777X as “an absolute peach”.

Key to his enthusiasm is the aircraft’s economics and greater space — it is 20 per cent more efficient per seat than the industry’s long-time benchmark, the 777-300ER, and its cabin is wider with bigger windows. The 777X combines the best features of the current 777 with a longer fuselage, new engine and the composite wing design from the Boeing 787.

Other airlines that have ordered the 777X are Lufthansa, Etihad Airways, Qatar Airways, Singapore Airlines, Cathay Pacific Airways and All Nippon Airlines.

Qantas’ competition, called Project Sunrise, also includes the Airbus A350 and the airline is demanding Sydney to London nonstop capability with 300 passengers.

Airbus and Boeing said they could meet the airline’s demands or close to it. Qantas plans to add underfloor bunks to the winner of its competition because on ultra-long-haul flights the aircraft will carry virtually no cargo, just passengers’ bags. Air New Zealand is going to accelerate its redesign of its interior offering at its Hangar 22 seating project after it decides on either the 777X or A350 in April.

Air NZ chief executive Christopher Luxon told AirlineRatings.com at the inaugural of the airline’s first service to Chicago last week that the airline had been bringing customers through to experience mock-up cabin spaces in an attempt to learn their thinking about space, storage and privacy.

“We’ve been running customers through a number of mock-ups that at this stage are quite primitive and quite conceptual but are giving them a feel about what they want to play back to us around that,” he said.