On the technical side, the big appeal for airlines is that over 70% of the A350 XWB's airframe is made from advanced materials that combine composites (53%), titanium and advanced aluminum alloys.
The A350 XWB is the first Airbus passenger jet to use both fuselage and wing structures made primarily of carbon fiber-reinforced polymer, resulting in lower fuel burn as well as easier maintenance, according to the company.
Its rival, the 787, is one of the most advanced airliners launched in recent years, and is made up of 50% composites and uses 20% less fuel than other aircraft in the same category.
Paris Air Show hopes
Industry experts said ahead of the test flight that there was an outside chance the A350 XWB might be spotted in the skies at the air show, even though Airbus had said the plane would be too busy carrying out flight tests to attend.
"We're still waiting to find out whether the A350 will put in an appearance," said Murdo Morrison, editor of aerospace industry magazine Flight International.
"That certainly would be a highlight -- it's one of the newest and most exciting aircraft, but it and Bombardier's C-Series are at a critical point in their development.
"It becomes a bit of a fight between the marketing people, the publicists, who want the company to get all the best headlines, and the engineers who are working to critical deadlines to get the plane ready to fly as soon as possible," he explained.
"What may happen is they pop in for one day -- fly in and then fly out again -- or even, in the case of the A350, that they do a flypast, without even landing."