Boeing's third 787 flight test aircraft has returned home to Seattle for additional inspections on its horizontal stabiliser, following weekend inspections.

ZA003, which has been based at Pinal Air Park in Marana, Arizona since 22 June for high-intensity radio frequency (HIRF) testing, returned home to Boeing Field in Seattle.

Programme sources indicate that following the aircraft's Sunday return to Boeing Field, ZA003 was set to continue horizontal stabilizer inspections which began 25 June, potentially indicating a discovery and further diagnosis of scope of the improperly installed shims and over-torqued fasteners.

Boeing declined to comment on ZA003's return from Marana, citing a policy not to discuss flight test operations.

ZA002 returned to flying on 27 June to conduct autopilot functional tests.

Programme sources also indicate that flight tests that were previously assigned to ZA003 late last week have been reassigned to ZA002 for testing on Monday. ZA005, the GEnx-1B-powered 787, is expected to make its second flight Monday as well.

The inspections were prompted following the discovery of workmanship issues that included improper installation of shims and fastener over-torquing in the horizontal stabiliser manufactured by Alenia Aeronautica in Foggia, Italy.

If left unaddressed the fasteners and shims, or engineered fillers, can create a long-term fatigue issue on the structure.

ZA003 is slated to be the first aircraft to make its international debut at the Farnborough air show in mid-July.

The aircraft is outfitted with a partial interior along with racks of instrumentation to test the aircraft's cabin systems.

Boeing aims to certify and deliver the 787 to Japan's All Nippon Airways by years end.

Source: Air Transport Intelligence news