747-8F Testing: RC503

747-8f testing continues apace. Seen here at the south end of Paine field is RC503 (test registration N5503S msn: 35807), the fourth test aircraft in the program and the only one in customer colors (in this case, Cargolux’s new livery). Several other 748f frames are painted and awaiting engines, but only this one is in the flight test program and the only one based at Paine field (the other 748f test aircraft are located at Palmdale, California and sometimes Grant County, Washington). In a minute or two, RC503 will head out for Grant County, part of a trio of test flights it undertook on December 4.

RC503 rolled out of the paint hangar in June and first flew in July, and has been racking up hours since then. The discovery of some vibration and issues with the inboard aileron actuators (located between the inboard and outboard TE flaps, just after the inboard engines) have pushed EIS to mid-2011, but fixes seem to be already underway and flight tests continue apace. Recently, test aircraft RC521 (test registration N5017Q, msn: 36136) was seen at Yuma, Arizona, with revised actuators and with special paint applied for air-flow tests over the inboard engines and pylons.

Photographer: Alex Kwanten