Who better to give a commentary on the “secrets” of the Singapore Airlines’ first A380 in Toulouse this week than resident Qantas engineer Paul O’Donohue.

O’Donohue was overheard calling the features over his mobile to head office (one assumes) during a walk through of both decks of the super jet some call Jetzilla.

O’Donohue wasn’t a spy. He was an invited guest. It is just that Qantas CEO Geoff Dixon and every other head of an airline that has ordered the biggest passenger jet yet built were no-shows at the grand handover of the first production model to Singapore Airlines, apart from Qatar. But it sounds like Dixon knows all about what Qantas will face from Singapore Airlines in the battle of the biggest jets when both fly them in direct competition from next August.

“Yes… it’s one by two by one in business class… four across in all… yes.”

O’Donohue’s reaction to the two double bed suites in the first class section couldn’t be overheard. Not in the push and shove of the European media and a half dozen television crews trying to do live crosses in a giant scrum of tripods, cables and anchor personality egos.

But it might be a case of reaching for the redrawing boards at Qantas, since it has said it will put its business class A380 customers in two by two by two seating, compared to four across in total in Singapore Airlines.

The real story about Jetzilla isn’t about the bitching over who will have the fanciest fit-out, but the carbon footprints of the beast.

The A380 does 2.9 litres/100 kms per passenger with 470 seats. The average fuel consumption for the 12,000 jets that do almost all the scheduled flying now is 5.5 litres/100 kms per seat.

Airbus sales supremo, John Leahy, says that by 2025 nothing (much) will be flying with fuel burns per person that aren’t at least as frugal as those of an A380 in 2007.

But Airbus and Boeing also claim that by 2025 there will be around three times as many people flying as today. Which even by A380 equivalent standards, means 50% more carbon pollution than now.

Leahy’s answer is in the technology of 2025, not 2007.

“We already have airlines telling us they are interested in 800 or more people in an A380 in low fare configurations,” he says. “That’s going to bring fuel down to less than 2 litres/100 kilometres per person for a rising proportion of the total uplift.”

Leahy argues that this rise in numbers of passengers and changes in the mix of tight fit low fare flyers to diminishing proportions of luxury class flyers could depress the total carbon footprint to no more than today.

It is a tall order, but the research goes on, as well as the rise in traffic. Technology has to keep delivering improvements to make Leahy, and his Boeing counterparts, turn the rhetoric into truly clean mass air transport.

Ben Sandilands went to Toulouse as a correspondent for Aviation Business Asia- Pacific.