Boeing has begun fatigue testing on the structural airframe of the 787 Dreamliner at the Everett, Wash on Sept 13, 2010
Fatigue testing involves placing the 787 test airframe into a test rig that simulates multiple lifecycles to test how the airplane responds over time.
According to Jim Ogonowski, structures vice president, Boeing Commercial Airplanes "Unlike static tests, where loads are applied to the airplane structure to simulate both normal operation and extreme flight conditions, fatigue testing is a much longer process that simulates up to three times the number of flight cycles an airplane is likely to experience during a lifetime of service".
While the structural test program already has validated the strength of the airframe, fatigue testing looks at long-term, continued use. The testing will be done for three years 24/7.
This is the natural progression of testing on a new aircraft and part of the process to achieve U.S. Federal Aviation Administration certification.