Boeing has started high-speed wind tunnel tests on a miniature scale model of the 777X aircraft, which features a 71m (233ft)-long composite wing.

The new phase of testing began the week of 6 January at Being’s transonic wind tunnel in Seattle.

The high-speed testing comes a month after Boeing began low-speed testing on a 777X model at a Qinetiq-owned facility in Farnborough, UK.

Initially the data from the wind tunnels will be used to correct any imperfections in Boeing’s software models that predict the performance of the aircraft.

In later tests, Boeing will use the wind tunnel data to refine the design and double-check that the model meets overall predictions about the 777X aircraft’s performance.

The composite wing on the 777X is the largest of any Boeing aircraft, and the fourth version of the airfoil design that originated with the 787. Boeing tweaked the design of the 787-8 early in the production cycle, then developed a new evolution of the composite wing for the 787-9.

Boeing launched the 777X in November and has 280 orders and commitments from five customers – Emirates, Qatar Airways, Etihad, Cathay Pacific and Lufthansa.

The programme is on track to reach firm configuration in 2015, Boeing says.

The 400-seat-class 777-9X is expected to enter service first around the end of the decade. It will be followed by the 350-seat-class 777-8X.

Source: Cirium Dashboard