Boeing is expecting widebodies to feature prominently at the upcoming Paris air show, even though it has curbed its 20-year forecast for long-haul aircraft.
The airframer predicts a need for just under 8,600 twin-aisle and high-capacity jets by 2032, with both sectors down from its commercial outlook last year.
But Boeing vice-president of marketing Randy Tinseth, speaking to Flightglobal in London, said: "I think this air show's going to be a widebody show."
He says the airframer is moving "closer and closer" to a formal decision on pressing ahead with the 787-10X, for which it has received a tentative order from Singapore Airlines.
"When the numbers are good we'll launch that aircraft," says Tinseth, referring both to customer commitments and technical specifications. Boeing is still pitching the twinjet as a 323-seat aircraft with 6,800-7,000nm range.
He dismisses Airbus's taunts that a double-stretched aircraft will not be competitive, insisting that the -10X will be a "simple" stretch, incorporating improvements built into the 787-9, while Airbus's A350-1000 has required a substantial redesign.
Boeing has yet to disclose a firm customer for the 777X. Tinseth is "confident" that it has the resources to pursue both programmes.
He says the primary concern with the 787-10X has been "more about the production system, when will it be ready for a third member", whereas the 777X is a "more complicated question" than the -10X because it requires a substantial review of technical and configuration aspects.
The 777-9X will have around 400 seats - compared with some 350 for the -8X - and the size of the jet blurs Boeing's normal boundaries in its forecast. It can be pitched at the airframer's high-capacity sector, the traditional domain of the 747, as well as the large twin-aisle category.
Tinseth illustrates the "overlaps" in the market by pointing out that although the airframer's 20-year forecast is for 8,600 long-haul jets, the 777X could address requirements for 3,500, the 787 for 5,000-5,500, and the 747-8 for 700.
Boeing has cut back further its outlook for the high-capacity market, from 790 to 760 aircraft. Tinseth says the airframer "over-forecast" demand for the sector and accepts that sales of the 747-8's passenger variant have "not been as good as we expected".
But he argues that orders for 262 A380s in the space of 13 years fail to give credibility to Airbus's predictions of an even larger market for the type, exceeding 1,300 aircraft.
"If we were overly optimistic, you could say [Airbus] was grossly optimistic," says Tinseth. "I think the market's taken care of that aircraft."
He says Boeing felt there was some demand for a large jet but that it "didn't justify building an all-new $20 billion airplane", and adds: "We're working hard to make sure there's a place in our product line for the [passenger] 747-8."