Today's 747-400 passenger fleet totals 482 aircraft operated by 32 airlines, with the largest single cluster being the 57 aircraft operated by British Airways from London Heathrow. A further 10 747-400s are flown by eight non-commercial operators in the government or VIP role.
The accompanying table compiled from Flight's ACAS database illustrates that only eight of the 32 747-400 airline operators have so far ordered the A380, meaning that one-third of the 13 A380 airline customers do not currently fly 747s.
"Airbus has ploughed some greenfield markets, racking up A380 orders from non-747 operators in the Middle East and elsewhere," says HSBC analyst Ed Stacey.
Almost a third of the A380s on order are destined for one operator - Dubai-based Emirates. Airbus has managed to overcome the disappointment of losing A380 Freighter customers FedEx and UPS by adding incremental orders for the passenger model from existing customers like Qantas - compensation for the delivery delays. But it has been a long time since a new customer was secured for the aircraft.
Indeed, Boeing's marketing operation likes to point out that the 747-8 has outsold the A380 by 87 to 16 since Airbus announced the production delay. Including the 747-400 and 747-8, the Boeing products also have outsold the A380 by 182 to 156 since the Airbus ultra-large airliner was launched.
Airbus chief operating officer customers John Leahy predicts that Airbus will take 20 A380 orders during 2007, but does not say whether these will come from existing customers.
Other than BA, the strongest prospects for new A380 customers are Cathay Pacific and China Airlines, which between them operate 37 passenger 747-400s. Asiana Airlines and EVA Air are also 747-400 operators with the potential to make the leap to the A380 or 747-8.
Air China, which has 12 747-400s, had been close to a deal to take aircraft from International Lease Finance before the production delays meant the A380 could not be delivered in time for next year's Olympic Games in Beijing. The carrier will now be high on both manufacturers' hit lists.
Airbus is forging strong links with China - a local A320 production line is already under construction - which should mean it is well placed to capitalise on the country's growth. The same is not true of Japan, which is a potentially huge market for the A380, as there are 62 747-400s operating with All Nippon Airways and Japan Airlines.
However, the Japanese airlines have shown little enthusiasm for the A380 so far (and, for that matter, the 747-8I), and Airbus has traditionally found it difficult to penetrate the Japanese market given the influence that its rival Boeing yields in the country. "I would be more optimistic about Airbus having success in China than in Japan," says Stacey.
Airbus already has one Indian A380 customer - Kingfisher Airlines - and the recent demonstration tour to the country shows how seriously it is taking prospects such as Air India and Jet Airways.
There are several current 747-400 operators that have declared a future strategy based around smaller aircraft - namely Air New Zealand and South African Airways. It is also unclear what future lies ahead for ultra-large aircraft in North America, where there is currently a fleet of 45 passenger 747-400s operating with two airlines - Northwest Airlines and United Airlines.
The 747-8I so far accounts for just over a quarter of the 87 orders for the new family, and Boeing views the present as slightly premature for sales opportunities for the passenger variant. The first wave of 747-400 operators reaching the 20 years in-service mark arrives in 2009 and peaks in 2011.
In total about 200 747-400s are expected to reach the standard retirement date between 2009 and 2013. Boeing expects to convert some of these aircraft to the passenger model of the 747-8, with the rest lost to orders for smaller types like the 777 - or to the competition.
However, Boeing may own a key advantage in the battle for passenger aircraft sales. With freighter sales accounting for the bulk of 747-8 demand, Boeing can live with a modest showing in the passenger market that still does damage to Airbus campaigns for the A380.
Kevin Roundhill, a regional director for product marketing at Boeing, says: "We're not going to sell the -8Is like -8Fs."