The upgraded engine forms the core of a broader set of aerodynamic and structural improvements that have been introduced since the freighter and passenger versions of the aircraft first entered service in 2011 and 2012 respectively. “Together with the other improvements made since entry-into-service on the 747-8F at the end of 2011, the engine PIP bundles 1.8% with another 1.7% for a total of 3.5% (fuel burn),” says 747-8 chief project engineer Bruce Dickinson. In addition to drag reduction and improvements to the cruise efficiency of the wing, the empty weight of the 747-8 has been reduced by almost 8,000 lb, while payload-range capability has been boosted through a 12,000 lb. increase in maximum take-off weight. The GEnx-2B67 PIP incorporates an all-new low-pressure turbine, as well as compressor, combustor and turbine improvements derived from the second batch of upgrades (PIP II) devised for the GEnx-1B engine on the 787. GE provisionally expected a 1.6% fuel burn improvement but, based on positive test data, upped this to 1.8%. The package of upgrades was launched after pre-delivery flight tests revealed a fuel burn performance shortfall in excess of 2%.