The largest member of a single-aisle Boeing NMA would be longer than the Boeing 757-300. Photo: Delta Air Lines.
Whatever the new airplane is, the general specifications are aircraft up to 250 passengers in two classes and a range of up to 5,000nm.
There is also agreement the airplane must start across from the A321neo. Configurations vary widely, but 190-200 seats in two classes are common.
Boeing CEO David Calhoun said on an earnings call that the next new airplane will compete with the A321 and cover the Middle of the Market.
A single-aisle, 250-passenger airplane would be longer than the 757-300.
Technical build challenges, while not insurmountable, exist with long, thin airplane.
Gate and ramp space constraints accompany a long airplane.