Boeing plans improvements to 747-8

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Boeing intends to return the 747-8 passenger and freighter to within 1% of the original planned service entry specification by 2014, with a series of systems, airframe and engine upgrades.

Starting later in 2012, Boeing will begin by providing interim functionality to the 747-8's avionics and flight management computer, activating the "quiet climb" and precision navigation functions of the 747-8's autopilot, said 747-8 vice-president and chief project engineer Bruce Dickinson.

Dickinson said company meetings to discuss establishing full functionality for the 747-8's avionics began on 28 February.

In 2013, Boeing and General Electric will certify an engine performance improvement package (PIP) for the 747-8's GEnx-2B67 engines, shaving 1.6 percentage points from the 2.7% fuel-burn shortfall that existed on the freighter at time of first delivery in October 2011.

The GEnx-2B PIP draws directly from changes first designed for the 787's GEnx-1B's PIP2, which modifies the engine's high-pressure compressor.

Currently, the fleet of 747-8Fs in operation have seen a roughly one percentage point better-than-expected observed fuel-burn performance measured against the 2.7% fuel-burn shortfall on the aircraft, said Dickinson.

Dickinson said Boeing aims to reactivate the 747-8's locked-out 12,500l (3,300 gal) horizontal stabiliser fuel tanks in 2013. These were deactivated after an analytical model showed that a flutter condition could occur in the event that a wing strut failed while the tail tanks were filled above 15%. No details were provided of the fix for the tanks.

The following year, in conjunction with GE's PIP, through a combination of reducing the aircraft's empty weight by 2,270kg (5,000lb) and cleaning up its aerodynamic profile, the 747-8 will be "within 1% of where we said we would be from the beginning", said Dickinson.

Dickinson added that some of the excess structural weight has been converted into structural capability, enabling Boeing to increase the maximum takeoff weight of both the freighter and passenger models by 6t to 448t.