A COMPOSITE wing-box test article built by Northrop Grumman for the Rockwell X-33 re-useable-launch-vehicle technology-demonstrator programme reached its ultimate design load and predicted failure load during tests at NASA's Langley Research Center. The wing-box, manufactured of carbonfibre-reinforced bismaleimide, buckled at a load of 40,000kg, and failed at the predicted load of 48,000kg.
Source: Flight International