Boeing's Phantom Works is redesigning its Advanced Theatre Transport (ATT) concept with a forward-swept tilting wing to improve the aircraft's centre of gravity (CG) position, while it decides between a short wide fuselage or a more slender conventional configuration.
Following a recent "non-advocate" review of the super short take-off/landing ATT programme by Boeing engineers, it was decided to drop the conventionally-swept 39m (128ft) span wing in favour of the 7-9° forward sweep. "This addresses CG stabilisation and gives a much bigger sweep spot when loading," says Lorin Bliss, ATT marketing manager. The new ATT wing will also pivot from the front, tilting downwards to the rear. The original design called for the wing, which would be wet and fully blown, to pivot from the rear up to 42° using two screwjack actuators.
The new design will reduce the weight of actuation systems and remove the need for a large upper fuselage/wing fairing forward of the leading edge. The objective remains to land on a 228m (750ft) rough strip in hot and high conditions - 4,000ft at 35°C (95°F) - and deliver a 27t (60,000lb) load. Added attention is also being paid to lifting loads from short unimproved airstrips.
Boeing is continuing trade-off studies between a shorter 'fatboy' fuselage and a narrower Boeing C-17 size fuselage barrel. Designers are trying to strike a balance between carrying wide loads and the weight and cost advantages of producing a more slender fuselage.
Boeing, which is largely funding the programme, plans to modify its 7% scaled ATT model and repeat earlier tests.
Source: Flight International
