A Boeing 787 will be on display at next month’s Farnborough air show outside London, but perhaps more attention will revolve around a Boeing jet that can only be seen in artist concepts: The reengined 737 MAX. At issue is how much Boeing can close its gap with the Airbus A320NEO, which has won 1,425 firm orders, compared to 451 for the MAX.

There is no doubt that the NEO stole the spotlight at last year’s Paris air show. Airbus announced hundreds of orders at Le Bourget for the reengined, more efficient narrowbody aircraft, leaving Boeing executives looking flat-footed as they maintained they still had time to decide whether to offer a new engine on the 737 or develop a brand-new jet that would enter service several years later. “There’s no need for an artificial deadline, and by the end of the year we’ll have got more direction,” maintained Boeing’s Mike Bair, vice president of advanced 737 product development. But just a month later, his company hastily announced it would offer the MAX as an alternative to the NEO.

Can Boeing turn the tables this year at Farnborough? The U.S. airframer has long maintained that it no longer sits on orders so it can unveil them with a big splash at signature air shows. But with Boeing still smarting from the NEO’s runaway success in 2011, that may not be the case this year. A strong showing at Farnborough would help Boeing prove that the NEO’s head start—it has more than three times as many orders as the MAX—is only a temporary advantage that will even out over time. One possibility: A big MAX order from United Airlines, a prospect Wall Street analysts have been speculating about since April.

Another developing aircraft that will be closely watched at Farnborough is Bombardier’s CSeries. Launched at the U.K. show four years ago, development of the 110- to 130-seat jet is now entering a critical phase, with just six months to its scheduled first flight. Bombardier officials acknowledged last week that the program was experiencing some supply-chain hiccups, but insist it is under control and encountering nothing like the huge setbacks that delayed the 787 and Airbus A380 developments. What Bombardier could use is more orders to provide market validation for a jet that is invading the lower end of Boeing’s and Airbus’s turf. Will such sales materialize at Farnborough?

Cameron Doerksen, an analyst at National Bank Financial in Montreal, says Bombardier is ‘emphatic’ that more CSeries orders are in the pipeline. But he also dismisses the idea that the program would be in trouble if none are announced at the show. “From an order point of view, the CSeries is ahead of Embraer’s E-Jet program at the same point in development,” he notes.

Last summer, exuberant Airbus officials hailed the Paris event as their “best air show ever.” In a less than a month, we will see whether Bair and the Boeing team can make a similar boast this year.