During the testing, the crew will introduce a range of vibration frequencies to the flight control surfaces by physically hitting the yoke or by computer input. The tests will ensure that the aircraft structure naturally dampens out the oscillations without further input from the pilots, and without amplifying into potentially destructive open-loop feedback oscillations.
The flutter test phase, which also includes additional primary flight-control system evaluation, is expected to be followed by a further period of stability and control tests.
The certification campaign is scheduled to be completed in the second quarter of 2014, with delivery to launch customer Air New Zealand set for mid-year. In addition to the ZB001 and the second test aircraft ZB002—both of which are powered by the latest “Package C” version of the Rolls-Royce Trent 1000—the test program includes a third airframe, ZB021, which will be powered by General Electric’s GEnx-1B.