Boeing is confident that improvements it is implementing on the 747-8 will recover performance to beyond customer guarantees and bring it "very close" to the original brochure claims made at the time of launch.

The airframer is introducing a block change in 2014 that will incorporate a combination of improvements including upgraded General Electric GEnx-2B engines, updated flight management computer capabilities and modifications to allow the tailplane fuel tank to be reactivated. This was locked out after a flutter condition was discovered during flight-testing.

These various upgrades will be flight-tested next year.

"At this point, the committed block point improvements get us very, very close to where we committed to be at the start [of the programme], but not beyond it. But it's beyond guarantees back to where the original 2006 brochure fuel burn and operating cost levels were," says 747 programme manager Elizabeth Lund.

Speaking on board the 747-8I's first passenger service, flown by Lufthansa between Frankfurt and Washington Dulles on 1 June, Lund outlined the key product developments that will come together on 747-8s being delivered from 2014: "The GEnx PIP [performance improvement package] will be big. We're upgrading the FMC and some of the other flight control software systems and we are continuing to take weight out of the airplane, so we're looking at the latest generation structural designs that will continue to improve the performance. We're also looking at new IFE [in-flight entertainment] systems and other new interior features."

A new FMC was developed for the 747-8, which was introduced when -8F deliveries began last year, and a major revision was made on the first 747-8I for Lufthansa, says Lund. "This was the second generation of the FMC, and we're going to introduce a third - block point three - which will add more functionality.

"The first generation could do virtually everything the 747-400s could do and a little more, and we keep adding steps."

Lund says that the changes are all software rather than hardware driven. "The block point three will have the latest RNP [required navigation performance] capability, some climb and direct route capability that allow you to maximise efficiency."

The key packages such as the FMC upgrade and GEnx PIP, along with tailplane fuel tank modifications, will be introduced in "one big block change" in 2014 after flight-testing is completed next year, says Lund. Other upgrades will be incremental.

"With these improvements, the 747-8's seat/mile costs are on the same horizon line as the 777-300ER," Lund says.

She adds that while the seat/mile performance may be no better than its smaller sister, the 747-8 comes into its own on dense routes with high traffic volumes: "We're 75-100 passengers more than the -300ER and it's about the revenue from the delta passengers, so if you can fill it, the 747-8 can make you a ton more money. So if you have route structures that can fill it which absolutely exist or, if like Lufthansa, you can fill a very large business class, then the 747-8I is a fabulous aircraft."