Most of you were right on with the photo I posted yesterday. It is a Boeing 747-200 that was the test bed for Rolls Royce to test the Trent 1000 for certification taken at the Future of Flight in 2007. The odd part of the photo was engine #3 was a bit larger than the other three.
The aircraft was purchased by Rolls Royce from Cathay Pacific Airlines. The engine was being tested to be used on the Boeing 787.
One of my readers, Ian, found additional pictures of the aircraft in flight from Flight Global.Image: TheNewArea51