RogerTangoFoxtrotIndigo,
It's not that RR does not offer an engine for the 747-400ERF.
RR would love to put the RB211-524G/H on it. The 747-400ERF did not get deriv engines from GE and Pratt did it?
Maybe you should ask the folks under the flight path at Heathrow why there is no offering for the RR engine on the 744ERF.