Qatar Airways has boosted its Boeing 777X order to include ten of the long-range 777-8X jets alongside its standing order for fifty of the larger Boeing 777-9X aircraft.

The Boeing-friendly fillip, announced during this week's Paris Air Show, adds to a total of 320 orders and options for the advanced jet, which is expected to make its first commercial flight in 2020.

Boeing claims the 777X will be "the largest and most efficient twin-engine commercial jet in the world, with the lowest operating cost per seat of any commercial airplane."

The 777-9X is spec'd for 400 passengers in a three-class cabin layout with a peak range nudging past 15,185km (8,200 nautical miles).

Following the 777-9X will be the 777-8X, which will trim the seat count to 350 passengers but extend the jet's maximum range past 17,220km (9,300 nautical miles).

Earlier this month Qantas name-checked the Boeing 777X as a possible replacement for its Airbus A380s when the superjumbos are retired around the mid-2020s.

Qantas' partner and Qatar Airways' Gulf competitor Emirates plans to replace its entire Boeing 777 fleet with 777X jets from 2020, having signed on the dotted line for 150 of the 777X airliners.

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