Boeing is testing a service-ready 787 software load as part of its final steps toward the US FAA Type Inspection Authorisation (TIA), clearing the way for the commencement of the aircraft's formal certification campaign.
Boeing is using ZA004, the fourth flight test aircraft, as a testbed for its latest 'service-ready' software load to present a "conforming article" to the FAA to begin flight tests for certification, the company confirms.
The latest flight control module (FCM), which contains the software for the 787's fly-by-wire flight controls and control laws, has been going through "regression testing" to tease out any final bugs in the latest V5.5 software load.
While Boeing declined to offer specifics on what changes are included in the latest software load, programme sources say that the latest version addresses small issues or 'squawks' discovered during the first phase of 787 flight tests.
Those same sources add that pulling together the final service-ready software load has been a key pacing item for the programme and should clear the way toward TIA to occur by the end of March.
Following the TIA, personnel from the FAA will be invited onboard 787 flight tests to evaluate the aircraft for certification.
ZA004 has been ground testing the new software load since 10 March, and has been progressing in multiple blocks. The aircraft is expected to return to flight test around 15 March, followed by an additional stretch of ground tests before transitioning to Victorville, California for the start of Rolls-Royce Trent 1000 powerplant performance tests along with nautical air mileage (NAMs) tests to measure the fuel consumption of the aircraft.
Additionally, ZA003 is set to join the flight test campaign 14 March when the aircraft's first flight window opens at 10:00 PST (18:00 GMT). ZA003 will be the fourth 787 to fly, and will be the last of the Trent 1000-powered aircraft to join the test fleet. The partially instrumented aircraft, which is fitted with an proper interior, will focus primarily on tests of the passenger and crew environment.
Two additional 787 test aircraft, ZA005 and ZA006 will be powered by General Electric GEnx-1B engines, and are expected to join flight test by late-April.
Boeing has accumulated roughly 275h since 15 December as part of its 3,100h flight test programme expected to culminate in delivery to Japan's All Nippon Airways in the fourth quarter.