"This is the first major development milestone for the program since we launched the program last month," said Terry Beezhold, vice president and chief project engineer of the 777X program. "Wind tunnel testing will validate our performance models and generate a vast amount of data that our engineering teams will use to design the airplane in this phase of development." 

Testing started on Dec. 5 at QinetiQ's test facility in Farnborough, U.K. Wind tunnel models allow experts to test many different configurations for the airplane. Low-speed tests measure airplane performance with a variety of high-lift surface settings to simulate takeoff and landing conditions. 

The low-speed model currently being tested is a 5.5 percent scale model of the baseline 777X, measuring about 4.22 meters (166 inches) long with a wing span of 3.92 meters (154 inches). Hundreds of sensors are embedded in the model to measure pressure to determine the in-flight loads as well as provide valuable diagnostics of the aerodynamic performance of a given design.