EVERETT - RC001 is airborne on its maiden sortie as of 9:59 AM PT. Live continuing coverage of the first flight of the 747-8I from FlightBlogger and flightglobal.com.
SEATTLE - 11:40 AM PT: We've relocated down to Boeing Field while RC001 is out over Eastern Washington at 14,000ft and all looks to be going smoothly. Because this aircraft will start by undergo flutter evaluations, this first 747-8I does not have the outboard aileron modal suppression (OAMS) system installed, which is designed to dampen the wing vibration on the 747-8F. Boeing will wait to see if the vibration, also known as a limit cycle oscillation (LCO), is present on the -8I which has structural differences from the freighter with its elongated upper deck.
UPDATE 11:59 PM PT: Brian Johnson, 747-8 deputy test programme manager says the primary conditions for today's first flight mainly center around initial air worthiness evaluations on a standard B1 profile. Johnson says Captains Mark Feuerstein and Paul Stemer are currently conducting engine shutdowns and re-lights on the four General Electric GEnx-2B67s.
Also here's the Google Earth track over the first hour of the flight. Hat tip to @lesmond: