September 11, 2013
Credit: Liz Matzelle
Boeing is closing in on the first flight of the stretched 787-9 by starting the first series of ‘gauntlet’ ground tests that simulate the operation of major systems.
The initial tests are focused on the flight control system, and come as ground test engineers calibrate the 787-9’s navigation and airspeed sensing devices.
The first test aircraft, ZB001, is located at Boeing’s Everett, Wash., facility, and ultimately will be joined in the flight test campaign by two further development airframes—ZB002 and ZB021—as well as a production-configured 787-9, which likely will join towards the end of the test early in 2014.
Assuming no issues emerge during this initial test phase, Boeing is expected to move into a final gauntlet test sequence later this week, which exercises the systems in a closed-loop simulation of the first flight.
If the manufacturer follows the procedure used for the final run-up to the first flight of the 787-8 in December 2009, the final gauntlet tests will be split into two primary blocks. In the 787-8 program, this began with simulation of a typical ‘B1’ first flight profile, the standard checkout of all aircraft systems as part of normal production testing. The second block was a more rigorous “first flight” final gauntlet which covered an expanded profile of tests and failure scenarios.
The 787-8 gauntlet testing began around Dec. 8, and first flight followed on Dec. 15. However the schedule for the 787-9 may not follow the same path. The 787-8, for example, already had completed an initial gauntlet series earlier in the year before Boeing decided late in the build-up sequence to delay first flight because of a side-of-body wing join structural issue, and the December testing reflected lessons learned during the earlier runs. The 787-9, on the other hand, already takes advantage of the vast systems experience amassed on the baseline model, but incorporates changes that reflect the move to the new derivative that is 20-feet longer than the 787-8.
Ground tests have been underway since ZB001 rolled out on Aug. 24. The certification effort for the 787-9, which is configured to carry 40 more passengers an additional 300 nm. than the 787-8, is expected to last around six months. While Boeing has not detailed plans for the flight test program, this provides ample margin for pre-entry-into-service testing before the first delivery to launch customer Air New Zealand in mid-2014.