Freed from compromises for the short-range (SR) requirements, the baseline and stretch versions of the 7E7 have been adjusted upwards towards the original performance targets outlined earlier this year. The baseline range is now back to 14,400km (7,800nm) from 12,210km, while span has grown again from 56.7m (186ft) to 58.8m.

The overall body length remains at 55.5m while maximum take-off weight (MTOW) has climbed to 205,400kg (452,500lb) from 186,100kg. The stretch length remains unchanged at 61.6m, but span increases in step with the baseline model and MTOW grows to around 227,000kg in line with a range increase to 15,360km from 14,800km.

The SR range is more specifically tagged at around 6,480km with a single-class layout of 300 passengers, versus around 200 and 250 in the three-class base and stretch, respectively. Span is expected to be kept at below 52m for gate compatibility reasons, while other dimensions will be retained. "To make sure it's going to be a spectacular short-range aircraft we're going to be making the wing lighter by de-gauging it," says Boeing 7E7 senior vice-president Mike Bair. The wheels, brakes and fittings will also be made lighter, along with other "significant changes in the structure". In place of the optional wingtip treatments studied earlier, Boeing is now looking at "something more dramatic than clipping the wings", says Bair. Options include blended winglets or split upper and lower projecting winglets similar to those developed for the MD-11.



Source: Flight International