Ground testing on ZA001 and ZA002 has all but slowed to a snail’s pace compared to the blistering rate of pre-flight testing before and during last month’s Paris air show. The slow down is not unexpected given the emergence of structural issues with the wing root and the urgent behind-the-scenes engineering effort now underway to swiftly develop, test and implement a fix that will clear the way for first flight.

Most of the flight test team allocated to ZA001 were given a rare weekend off, with nothing scheduled until tomorrow. Recent tests completed last Friday included stall warning system checks, electronic engine control interface connections, navigation radios and verification tests of the airspeed indication system.  

Testing on ZA002, parked expectantly on the Everett delivery ramp a few stalls to the north of ZA001, has also been subject to slippage. However a big day for ZA002 appears to be approaching on July 16 when the aircraft’s engines are due to be started for the second time and a myriad of systems checks are set to take place. Chief amongst these will be a high-lift system ground test using engine-supplied electrical power as well as flight deck checks of the crew alerting audio system.

Another key system due for checks on ZA002 is the gross weight center of gravity processor, originally set for tests on July 12. This is also now scheduled for tests on Thursday and will be an important tool for flight test work in the coming months on ZA002 which will verify 787 stability and control along with ZA001. The processor will allow flight test personnel to precisely monitor and alter cg positions in-flight to enable tests of several conditions in a single sortie.