Relentless testing of the 747-8 Freighter continues at Boeing while preparations gear up for the first flight of the 747-8 Intercontinental by the end of the month.
In recent days, test workhorse RC501 has been used for main landing gear door rigging tests, and earlier today flew from its temporary home at the former Norton AFB, San Bernardino, to Edwards AFB for landing roll out testing. The aircraft is also shortly expected to undertake Vmcg (minimum control groundspeed) tests at Edwards in which an engine failure on take-off will be simulated, and the minimum speed measured at which the direction of the aircraft can be maintained.
Yaw authority during Vmcg will be improved through use of 'spudder' - rudder and spoiler. (Guy Norris)
A maximum lateral deviation from the centerline of 30 ft (9.1m) is allowed under the critical engine failure case Vmcg certification test. With the 747-8’s outer main gear wheel span of 12.7m, a runway width of 45m allows 9.1m deviation plus an additional deviation margin of 7m before the outer main gear tire is at the edge of the runway. None of this should be a problem to the crew at Edwards where, depending on winds and traffic, the tests will either use the 91m (300-ft) wide runway 4R/22L or 61m (200-ft) wide runway 4L/22R.
Boeing is confident that increased yaw authority through the use of ‘spudder’ (spoiler and rudder), will give the 747-8 the same, if not better, maneuverability characteristics than the 747-400. Spudder refers to deployment of spoilers during large deflections of the double hinged lower rudder. The ground spoilers of the 747-8 are also rigged to deflect up to 60 deg (versus 45 deg on -400) to improve braking.
RC523, seen here poised to depart Paine Field on Feb 28, enjoyed a brief break from cold Everett with a trip to Kona, Hawaii (Joe Walker)
RC521, the second -8F test aircraft, has meanwhile been used for stall testing with artificial ice shapes attached to the leading edges of the wing. RC522 is currently being used for further testing of the outboard aileron modal suppression system with various payload configurations.
The crew of RC523 has been enjoying a brief respite from the recent spate of wintry weather in Seattle, and took the aircraft to Kona on Hawaii’s Big Island for tests in the unrestricted airspace around the island. The all-white painted freighter was due to return to Everett today. Sistership RC503 is meanwhile being used for flight management system tests following a flurry of autoland and alternate landing gear extension tests, the latter of which involved the use of one of Boeing Flight Test’s high speed T-38 chase aircraft.
Preparations for the first flight of the -8I meanwhile continue at Everett where Boeing’s ‘Big Orange’ RC001, has been going through the initial stages of several ground tests – one of the more recent being the primary flight control system. Meanwhile, here are a couple of video clips and photos from the roll out event last month. Apologies for the indifferent sound quality of the discussion clip.
(Guy Norris AWST/YouTube)
(Guy Norris AWST/YouTube)