Boeing is working through a long list of system checks, or engineering work authorizations (EWAs), on the first 747-8F before clearing the way for the start of flightline gauntlet tests of the type so familiar to anyone who has been following the saga of the 787 on its way to first flight.
RC501 awaits further ground tests at Everett (Guy Norris)
The fact that testing on RC501, the first 747-8F, has yet to reach the systems gauntlet stage suggests that first flight is still weeks away. Given the status of current work it seems Boeing is not likely to open up the first flight window until around the end of the month rather than mid-January as was speculated late last year. Officially all Boeing is saying is that “first flight will occur early in the year in the first quarter.”
Ground crews are currently working through tests of the air data inertial reference units (ADIRU), a key component of the 747-8’s navigation avionics suite. The ADIRU is the great-great-great grandson of the inertial navigation system (INS) which Boeing engineers were tweaking 41 years ago as they prepared the first 747 for flight in early 1969. The 747 was the first commercial aircraft to have an INS designed in it from the outset and was the first civil application of then brand-new technology originally hatched for the U.S. nuclear submarine and Apollo space programs.
Other ‘EWAs’ are underway on the angle-of-attack sensor system, primary flight control system, flight management computer and the on-board processor which works out the aircraft’s center-of-gravity. The fact that the EWAs are edging closer to the gauntlet tests is backed by evidence that the flight control system evaluation late last week was supported by Boeing’s patented flight emulation test system (FETS), which provides the simulation scenarios required for the flightline gauntlet.
RC521 - the second 747-8 - outside for the first time at Everett. (Matt Cawby)
Work is also underway on the second aircraft, RC521, which is now on the Everett ramp after rolling out of Building 40-22 earlier this week. The current tests are focused on early calibration of the same center-of-gravity processor that will be used during flight tests. Early test work is also underway on RC522, now in the slant position nearest the door inside Building 40-22. The current work is aimed at operating tests of the aft 104 inch x 66 inch lower lobe cargo door on the aircraft’s right hand side, and design verification tests of the larger 122 inch x 134 inch main deck cargo door on the aft left side.