Boeing has completed a test flight of a 747-8 Intercontinental with a performance improvement package (PIP), including enhanced General Electric GEnx-2B engines that will boost the aircraft's fuel efficiency.

The flight took off from Paine Field in Everett, Washington on 20 May at 13:30 local time and landed at Boeing Field in Seattle about four hours later, says the airframer.

"It was a great flight and the engines performed as expected," says Boeing flight test and evaluation captain Kirk Vining, who operated the aircraft along with chief pilot Mark Feuerstein.

The PIP, which comes with improvements to the engines and flight management computer software, will provide an additional 1.8% improvement in fuel efficiency, says the airframer. This is higher than the 1.6% improvement previously targeted for the PIP.

Entry into service of the enhanced engines and flight management computer software will take place in late 2013. The airframer will deliver the first aircraft with the PIP in early 2014, and will make it available for retrofit.

"These improvements are a part of our commitment to continually improve our great airplanes for our customers," says Eric Lindblad, vice president and general manager of the 747 programme. "Improving fuel efficiency by another 1.8% saves the airlines approximately $1 million per year in fuel per airplane and reduces the carbon footprint."

The test programme for the PIP will also validate the design changes and test the operation of the horizontal tank fuel system of the passenger version of the 747-8, which was deferred from the first deliveries, says Boeing.

Sales of the 747-8I have been sluggish since the type was launched in 2006. Boeing has sold only 31 747-8Is to four airlines, with another nine ordered by VIP customers.

In April, Boeing decided to cut production of the 747-8 to 1.75 aircraft per month in early 2014, due to weak demand for both the passenger and freighter versions. The cut represents a 12.5% reduction from the current rate of two aircraft per month.

Source: Air Transport Intelligence news