“The honeymoon has lasted longer than on previous aircraft: people go out of their way to fly on [the A380 very-large airliner],” according to Airbus programs executive vice-president Tom Williams. By the beginning of this month, the European manufacturer had delivered 103 aircraft from the 262 for which it holds firm orders, leaving a backlog of 159, equivalent to about six years’ production.

“More important than the [reducing] backlog is the number of A380 passengers,” said Williams. Since the aircraft entered service in 2007, some 40 million passengers have been flown as the global fleet has logged 922,000 flight hours during 109,000 revenue flights.

New this year has been an optional 575-tonne variant that Airbus says provides a 15-tonne increase in maximum take-off weight (mtow). Structural reinforcement has been applied to the centre wing box, Section 15 primary structure, and the belly fairing.

Airbus now offers five “primary weight variants” for the A380, two either side of the basic 560 metric tons. The lowest, 490-t value permits the aircraft to comply with London Heathrow’s QC1 departure noise level requirements, while the new 575-tonne limit provides QC2 maximum payload-range, equivalent to 8t extra payload for the same (almost 7,000 nm) range or 500 nm more range for the same (525-passenger) payload, according to Williams. This gives the A380 “network flexibility in payload-range with a single build standard.”

Product improvements implemented in 2013 are claimed to provide “structure and systems enhancements for real operational benefits.” Changes include introduction of a light Inmarsat SwiftBroadband (SBB) antenna with less drag, which Williams says has become important “especially because in-flight entertainment system requirements have meant bigger antenna.” Airbus has also added auto-pilot/flight-director traffic-alert and collision-avoidance system alert prevention, and “soft” go-around procedure.

An enhanced A350-type load-alleviation function takes angle-of-attack and inertia information to estimate gust velocities that on-board computers use to command elevator and/or aileron movement. This alleviation means that Airbus has not needed to “put metal in place in case it is needed,” said Williams, who reported that there had also been “a little work [to add] about half a degree of wing twist (within jig tolerances) to optimize aerodynamic airflow, particularly on the inner wing, to improve drag.”

Enhanced engine performance, which “will never stop,” have meant a 0.5-percent improvement in specific fuel consumption for both Rolls-Royce Trent 900 and General Electric/Pratt & Whitney GP7200 engines and an up to 1.3 percent improvement since entry into service (EIS).

The A380’s higher weight option is accompanied by a new cabin layout for the double-deck airliner, which Airbus now has revised to 558 passengers, compared with the initial 525-seat configuration, according to marketing senior v-p Christopher Emerson. The latest configuration comprises ten 82-inch pitch first- and 84 61-inch pitch business-class seats on the top deck and 464 32-inch pitch economy-class ten-abreast seats on the main deck. Offering “no compromise in passenger comfort,” the manufacturer claims a “further 7-percent lower cost per seat,” while saying that the very-large airliner can still be optimized with an 11-abreast high-density layout.

The smaller A330 twin-aisle twinjet has a manufacturing backlog of just over two years, with 262 remaining to be delivered from the 1,246 ordered by the beginning of June. The most recent increase in production to ten a month means that Airbus has achieved the “highest ever rate for a widebody,” according to Williams. For the 12 months to the end of March 2013, Airbus reports an operational reliability of 99.2 percent on A330-200 Enhanced aircraft, or 99.03 percent for the overall global fleet.

Airbus has steadily increased A330 production from 7.5 to ten aircraft/month since 2009, but the manufacturer has “held off” from going to 11/month until Chinese resistance to the European Commission (EC) emissions-trading system has been resolved, said Williams. "We have been trying to convince the EC that this is an initiative better conducted through the International Civil Aviation Organization, but this might be difficult to do.”

The A330’s latest 242t MTOW, launched in 2012, will be introduced in 2015 as an “A330 enhancement.” Williams said Airbus had learned lessons from the A380 wing design that had permitted it to “tweak” the aerodynamics to reduce fuel burn by one percent.

A330 changes, which began as design studies last year, include gust-load alleviation and increased fuel capacity. Detailed design is under way, with integration and qualification continuing through 2014-16. The latest enhancements are expected to enter service in mid-2015 on the A330-300, followed by the smaller Series 200 in early 2016.

A new A330-300 centre-section fuel-tank option adds a further 41,560 litres capacity to provide an overall 139,090 litres. The development adds 250kg (550 pounds) to the operating empty weight, including pumps, tank inerting, sealing, and unusable fuel. At the new, higher 242-t maximum take-off weight, range with 300 passengers will increase to 6,100 nm from the 3,950 nm available in 1994 with the original 212-tonne aircraft, according to Airbus.

Airbus claims a “constantly growing” customer base for its A330-200F cargo aircraft, with 22 machines delivered to eight operators worldwide. Williams said that the variant had been launched into “probably the worst imaginable” market, in which “it is very difficult to sell at the moment.” Airbus expects demand to return, but “it could take two years.”

Williams warned that the freight market also might have changed during the global economic recession, with some high-value goods in future being transported by sea. Two new A330-200F operators this year are Tampa Cargo and Qatar Cargo, the latter flying three aircraft leased from BOC Aviation.