When programs are delayed, there is usually more than one reason. In the case of the MRJ, the project team fell behind in detailed airframe design, says Takaseki, although that work was completed by the time the delay was announced. From here on, the company expects only normal refinement of the design as it builds and tests the initial units. The first flight is due in the last quarter of 2013.

SkyWest's announcement has also helped drum up interest from other carriers, including North American mainline airlines, he says. While manufacturers commonly play up their chances of imminent sales, the studies of a rate increase suggest that the company is genuinely concerned it might have more demand than it can feed.

The company would like to shorten the delay but Takaseki does not sound optimistic when he stresses that the priority is on protecting the new schedule.

A longer development program means paying engineers for longer, and in this case pricey foreign engineers flown in to help sort out the problems are in the mix. But the company says it is still aiming at completing MRJ development within the original budget of ¥180 billion ($2.3 billion).

Mitsubishi Aircraft is not taking advantage of the delay to improve the specification of the aircraft. Engine supplier Pratt & Whitney has, however, rescheduled development of the aircraft's PW1200G geared turbofan to make best use of the delay. Originally running in parallel with the similar engine for the Bombardier CSeries, the PW1200G is now following that larger turbofan, benefiting from its testing and allowing Pratt to spread out its engineers, says marketing director Jim Speich. Some can now work successively on the two engines, rather than side-by-side with colleagues.

While Mitsubishi Aircraft must consider the potential of every supplier to increase its production rate, Speich says Pratt, at least, would have no trouble delivering engines faster.