The competitive landscape in the 70-240-seat aircraft market is poised to shift as Airbus, Boeing and Embraer update their product strategies in the coming 12 months.

The stakes are high not just for the manufacturers, but also for the engine makers vying for aircraft positions.

And it is not always an open playing field. For instance, Boeing’s deliberations on 737 reengining have, so far, left International Aero Engines out of the loop, says IAE President/CEO Ian C. Aitken. Boeing has an exclusive engine supply relationship with CFM International on the current 737, and Randy Tinseth, Boeing Commercial vice president for marketing, declined to comment on whether the company will consider offering an engine alternative this time around.

Airbus, by contrast, has been clear that it wants to offer customers two choices , as it does now on its single-aisle family. Discussions with engine makers now center on CFM International, with a LEAP-X derivative, and IAE with a geared turbofan -based powerplant, says John Leahy, Airbus chief operating officer for customers.

But Aitken says IAE has not yet made a technology decision and is still weighing two- and three-shaft, as well as geared turbofan, options.

Airbus wants its reengined A319, A320 and A321 to start reaching customers in late 2015, with a decision on whether to pursue the reengining to be made by the time the Farnborough air show takes place this coming July. Airbus is working toward slashing fuel burn by 15% over current standard A320s, which include the efficiency increases linked to new winglets being introduced.

Boeing’s decision to reshuffle its management team, in which Mike Bair was named general manager to head the Advanced 737 Product Development team after once leading the 787 effort in its formative years, also could have wider consequences. Tinseth notes that while crafting a 737 strategy is the priority, the 757 replacement question may be addressed as Bair reviews narrow-body plans more broadly. “Anything below a twin-aisle is going to be considered by Mike,” Tinseth said , while suggesting that the narrow-body replacement may not be single-aisle. Boeing built more than 1,000 757s, and Tinseth argues that “there is some need out there” for a follow-on.

Airbus believes its A321 is the natural replacement for the 757, but will face this more directly when it defines the sizing of its next-generation narrowbody, now not expected to enter service until 2024. Leahy argues that over time, markets tend to require larger aircraft and that those now served by 100-seat aircraft will require 150 seaters in a few years. That suggests Airbus may walk away from the approximately 110-seat A318 , which has never sold well.

Such considerations also are important as Embraer ponders its product strategy. Mauro Kern, executive vice president of commercial programs, says a firm decision is at least year away . Upgrades to the current E-170/190 regional jets are under study, as are new versions, such as a larger E-195X and aircraft still in the talking concept stage .

Meanwhile, Embraer is likely to face heightened competition starting in 2014, when Mitsubishi Aircraft expects its first regional jet to enter service. The the design of its MRJ regional jet is expected to completed by the end of the summer, when it is scheduled to proceed to the initial production stage.

The preliminary design review was completed last year. Mitsubishi says it is closely monitoring development of the key feature of the Pratt & Whitney PW1000G engine, its gearbox. “Up to this moment we are very happy about the results,” says Junichi Miyakawa, executive vice president.

Mitsubishi Aircraft has secured orders for 60 MRJs and says it is now in detailed talks with customers in the U.S., Europe and Asia. “Some customers are very interested in the MRJ100X in the European market,” Miyakawa, says. The MRJ100X is a 100-seat version of the basic design: the 92-seat MRJ90 will be certified first, then the 78-seat MRJ70, followed by the 100-seat MRJ100, although there is some question as to its viability .

Although much of the focus now is on the smaller aircraft segment, Boeing, for one, is mulling options to bolster the competitiveness of its wide-body line—specifically the 777—in the face of emerging competition from the Airbus A350-1000. The extent of Boeing’s effort is still being defined. S mall changes being planned would yield around 4% greater efficiency through airframe and weight reductions. A wingspan increase also is being looked at and, at the higher end, a new engine and rewinging. But Tinseth says Boeing is taking its time , noting the competition will not arrive until 2017; Airbus says the A350-1000 is to enter service in 2015.