Think-Dash

Excess weight keeps ANA's early 787s in the neighborhood:

At last week's 787 first delivery, Satoru Fujiki, an All Nippon Airways senior vice president, told reporters that the performance shortfall on the early deliveries would slot the aircraft into a role of regional missions, rather than long-range international flights, which will be flown with later built aircraft.

"The early 787s are actually much heavier than later-coming deliveries," he said. "So, for those aircraft we have taken an option to introduce those aircraft for domestic short haul and regional operations."

The comment was the first direct acknowledgement by ANA about the impact of excess structural weight the early 787s on the mission profile identified for the aircraft. Boeing has always maintained it would meet customer performance guarantees, though it was the clearest indication that weight gain would define the mission of the early aircraft.

The early deliveries, including Airplanes Eight and 24, are configured with twin Package A Rolls-Royce Trent 1000s with 64,000lbs of thrust and 264 seats for early domestic operations and will be updated to 222 seats when the missions expand regionally.

In short-medium haul operations, the required fuel for a long-range mission is traded for increased payload with a higher passenger capacity, and a shorter cruise phase lessens the impact of carrying the excess structural weight.

A recent report now provides some hard figures about the current weight of the aircraft. Aspire Aviation, which published a comprehensive report on the 787's performance Monday, writes:

According to Aspire Aviation's two sources at the US airframer, the first 787 prototype, dubbed ZA001 which carries the registration N787BA, is 9.8 tonnes (21,500 lbs) overweight, a significant figure when considering the aircraft's specific maximum zero fuel weight (MZFW) of 161,025 kg (355,000 lbs).

Line number 7 to 19 (LN7-LN19), the same sources confirm, are considerably less overweight at 6.1 tonnes (13,500 lbs). Line number 20 (LN20), the first 787 to feature increased maximum take-off weight (MTOW) from 219,539 kg (484,000 lbs) to 227,930 kg (502,500 lbs) to recover some of the payload/range capabilities lost owing to the overweight issue, is around 4 tonnes (8,800 lbs) overweight.

Line number 34 (LN34), dubbed ZA380 and the first 787 earmarked for China Southern Airlines, along with LN50 for Ethiopian Airlines, are block points for further weight reductions.

Line number 90 (LN90) will be the first 787-8 meeting the aircraft's original weight target with no overweight issue, the sources say.

The 21,500lb figure for ZA001 further confirms the same figure published in the Airbus 787 Dossier in December 2008, but the 13,500 and 8,800lb figures are the first public concrete estimates of the aircraft's structural weight gain. The figures also point to progress being made in the empty weight reduction of the aircraft, however the increased maximum takeoff weight is intended, in part, to regain the lost performance.

The increase in MTOW, allows for a higher structural payload to be carried, which can be accomplished by reinforcing the structure of the aircraft or adding load allieviation technologies that move lift across the wing to accommodate higher weight.

Air Lease CEO Steven Udvar-Hazy told this page in March at ISTAT: "My gut feeling is that the airplanes will always be heavier, and they'll just have more power and they'll just increase the max takeoff weight and say we still meet the spec. It's just going to become a heavier more powerful animal."