LONDON — Earlier today at the Farnborough Air Show, Boeing Commercial Airplanes (BCA) CEO Ray Conner confirmed that a stretch of the Boeing 777-10X is indeed technically feasible, according to a report by FlightGlobal’s Stephen Trimble.

According to Trimble’s report, Conner called a stretch of the 777-9X, which seats about 405 passengers in a standard three-class configuration, “straightforward,” but also noted that Boeing is still waiting to gather enough customer interest before launching the variant, which would add four rows to the airplane (40 seats in a standard 10-abreast configuration) and push the 777-10X above certain less-dense variants of even the Airbus A380, the world’s largest airplane.

Boeing may wait for Airbus to decide on A350-2000

The main holdup for Boeing is whether Airbus decides to launch a stretched variant of its Airbus A350-1000, which competes head to head with the existing Boeing 777-8X at about 350 seats. Unfortunately for the A350-1000, while it offers superior operating economics (CASM) to the 777-8X, the latter has managed to find a niche as the longest ranged airplane in the world and spiritual successor to the Boeing 777-200LR.

More damagingly, the 777-9X has better CASM than the Airbus A350-1000, and as those aircraft often compete head to head, the A350-1000 leaves Airbus hamstrung at the high end of the wide body market. In fact the 777X (with 306 orders) has about 63% market share against the A350-1000, which is higher than the current market share for the A320neo versus that 737 MAX. Adding in the very large aircraft (VLA) of the Airbus A380, Boeing 747-8, and the current generation Boeing 777-300ER pushes the actually pushes the advantage for Boeing since the launch of the A350-1000 in 2007 up to about 70% market share, almost dominant in the large wide body space.

Our analysis indicates that the Airbus A350-2000 (which has at various times also been known as the A350-1100), would reverse this advantage back to the Airbus court, drawing ahead on CASM as the A350 is the more efficient pure technical platform (the 777-9X draws its CASM advantage from added seating capacity). This would not be a massive CASM advantage but it would be tangible (1-2%) and it would position the Airbus product to win at least 50% share of large wide body orders moving forward.

Stretched 777-10X would be CASM king within 80m box

The problem for Airbus is that much as we outlined with a theoretical Boeing 737 MAX 10X as a response to the A321neo’s dominance, Boeing can counter with a simple and inexpensive stretch. Our analysis indicates that Boeing could complete a 777-10X for as little as $800 million to $1.2 billion. With 40 additional seats, the 777-10X would recapture the CASM crown in the head to head large A350 versus 777X contest, and retain Boeing’s lead.

And not only would the 777-10X retain an advantage over the A350-2000 in terms of CASM, it would also beat the Airbus A380. Our analysis indicates that the 777-9X already holds a slight edge in terms of CASM over the A380 in real world airline configurations when fuel prices are high, though the A380 retains its edge when fuel prices are lower (as they are presently).

The 777-10X would hold the edge over the A380 at all fuel prices. And unlike Airbus, who would perhaps proceed cautiously in launching an “A350-3000” similarly sized to the 777-10X for fear of cannibalizing A380 sales (a hypothetical “A350-3000” would also require a strengthened wing and thus be more expensive to develop than the 777-10X), Boeing only has to worry about affecting sales of the 747-8, which if it sells at all will only do so in its freighter variant moving forward.

Best of all, the 777-10X will manage all of this while remaining shorter than or equal to 80 meters in length, which would comfortably allow four additional rows of economy with 32 inches of seat pitch. 80 meters is an important figure because it is the length that large wide body gates, taxiways, and other airport infrastructure are currently designed for (an artifact of the Boeing 747’s popularity). With the same wing as the 777-9X, the 777-10X would still fit into the same 80 meter by 80 meter box at most airport gates, avoiding the need for costly airfield improvements (which has been a drag on A380 sales to some extent).

So the 777-10X makes a lot of sense in a world where the A350-2000 exists. The question is whether Airbus, which has stated that it worries about the cannibalization of existing sales from an A350-2000, will launch the aircraft at Farnborough. Most reports are that it will not, and until it does, the 777-10X is in a holding pattern.