Boeing remains circumspect about the possible launch of the NMA, as it continues to study the market for its proposed midsize airliner. Speaking Monday at the Paris Air Show, Boeing Commercial Airplanes CEO Kevin McAllister indicated that the company has yet to make a business case for the proposed NMA, right around the time Airbus officially launched the A321XLR, the long-range single-aisle jet ostensibly designed to serve some of the same markets targeted by its U.S. rival.

“Obviously I think one of the big pivots we’ve made as a company is to approach development programs where we drive as much of the definition of the program as far left as possible,” said McAllister. “That’s what we’ve done with the NMA. So when we talk about the business case, we talk not about just airplane size and configuration. We want it to meet the needs of a global base of customers, to be reflective of the dynamics we see today and the dynamics we see tomorrow, one of which is continued saturation of airports.”

McAllister also stressed the need to ensure a well-aligned production system and to “leverage every lesson” it learned on the 787, the 737, and even the defense business. “The other piece of this is the supply chain, to make sure we have the right supply chain targeted for the middle of the market airplane, as well as to make sure as we look at our services segment, that that’s accurately defined,” he said.

Last summer, just ahead of the Farnborough Airshow, McAllister said Boeing will need to decide on whether or not to proceed with NMA by the end of 2019 to safely meet a stated service entry target of 2025. Since then, Boeing adjusted its sights somewhat, moving its target for industrial launch to early 2020.

In the meantime, one potential engine supplier for the program—Rolls-Royce—withdrew from consideration due to a lack of sufficient maturing of its new UltraFan. During a recent briefing in Derby, Dominic Horwood, Rolls-Royce chief customer officer civil aerospace, said it had been a "difficult but responsible decision [but] the timing Boeing wanted just didn't align with our view of the UltraFan program...the NMA opportunity came up very early in our window [for post-Trent planning]."

Meanwhile the CEO of another major engine contender—GE boss David Joyce—has expressed some reservation about the size of the market, even after GE and CFM partner Safran agreed to propose a CFM design, despite the fact that the required engine thrust slightly exceeds the 50,000-pound limit the partnership’s remit would typically allow.